Wideband flat antenna

ABSTRACT

A broad-band plate antenna is configured such that an (N−1)th linear element portion among N linear elements consisting of first to Nth linear element portions has a length longer than an (N−2)th linear element portion, an area of the (N−1)th linear element portion is made larger in a direction of the (N−2)th linear element portion, or in a direction of the Nth linear element portion, or in a direction of the (N−2)th and Nth linear element portions, one feeding point is provided in the Nth linear element portion closest to a groundplate portion, the other feeding point is provided in the (N−1)th linear element portion second closest to the groundplate portion, and an area in the vicinity of a conductive portion of the (N−2)th linear element portion and an area in the vicinity of a conductive portion of the Nth linear element portion closest to the groundplate portion are connected to each other by a first conductor portion.

TECHNICAL FIELD

The present invention relates to a broad-band plate antenna, andparticularly to a broad-band plate antenna structure used withinequipment (a portable electronic apparatus such as a notebook personalcomputer) having a compact size, a small thickness and a limited space.

BACKGROUND ART

Conventionally, as frequency bands available for a cordless notebookpersonal computer, for example, 2.4 GHz band in accordance with IEEE802.11b and 5 GHz band in accordance with IEEE802.11a attaining atransmission speed higher than 2.4 GHz band have been put into practicaluse. Recently, 2.4 GHz band in accordance with IEEE 802.11g attaining atransmission speed as high as the above-mentioned 5 GHz band has alsobeen available. In addition, in some countries, the 5 GHz band that hasalready been widely used now covers a broad band including a lowfrequency and an intermediate frequency around 5 GHz band and a highfrequency around 5.8 GHz. That is, there is a growing tendency to covera broader band and multiband.

As described above, development of a plate antenna suitable for theportable electronic apparatus adapted to both of broad band andmultiband has been demanded. Currently, however, practical use orwidespread use of a plate antenna adapted to both of the broad band andmultiband has not been satisfactory.

FIG. 2 shows a notebook personal computer PC having an antenna attached,implemented by sandwiching a part of a plate antenna 19 in a gap betweenan liquid crystal (LCD) module 18 and a housing 16 in an upper endportion 15 of a display of notebook personal computer PC and coveringthe same with a plastic cover 17. In FIG. 2, z1 represents a mountlength of a composite element portion when mounted on the notebookpersonal computer, that corresponds to a length y1 of the compositeelement portion shown in FIG. 8 which will be described later, forexample. Meanwhile, z2 represents a mount length of a groundplateportion when mounted on the notebook personal computer, that correspondsto a length y2 of the groundplate portion shown in FIG. 8.

[Conventional Art 1]

FIG. 3 is an electrically equivalent diagram of a plate inverted-F-typeantenna 1 (hereinafter, referred to as an inverted-F-type antenna)according to conventional art 1, as disclosed in Japanese PatentLaying-Open No. 2003-37431. Inverted-F-type antenna 1 has aninverted-F-type antenna groundplate portion 1 a and an inverted-F-typeantenna linear element portion 1 b connected by an inverted-F-typeantenna element-to-groundplate short-circuiting portion 1 c. A singleelement feeding point 4 constituted of one feeding point 4 a and theother feeding point 4 b of a single element signal source 3 is providedon opposing surfaces of an inverted-F-type antenna one-end-open gapportion 1 d formed by inverted-F-type antenna groundplate portion 1 aand inverted-F-type antenna linear element portion 1 b. Plateinverted-F-type antenna 1 is adapted for use for a single frequency.

[Conventional Art 2]

FIG. 4 is an electrically equivalent diagram of a slot antenna 2according to conventional art 2. Slot antenna 2 has a slot openingportion 2 b (a non-conductive portion) formed in a slot conductiveportion 2 a. Single element feeding point 4 constituted of one feedingpoint 4 c and the other feeding point 4 d of single element signalsource 3 is provided on opposing surfaces of slot opening portion 2 b.Slot antenna 2 is adapted for use for a single frequency.

[Problems to be Solved by First Invention]

As described previously, inverted-F-type antenna 1 in FIG. 3 or slotantenna 2 in FIG. 4 are antennas adapted for use for a single frequency.Accordingly, in order to adapt to frequency bands of both 2.4 GHz bandand 5 GHz band, separate antennas for respective frequency bands shouldbe incorporated in an identical portable electronic apparatus. If theantennas are connected for use as a radio unit outputting 2.4 GHz bandand 5 GHz band from a single terminal, signals of both frequency bands,i.e., 2.4 GHz band and 5 GHz band, should be combined.

FIG. 5 is a diagram of an antenna multiplexer circuit 8 combiningsignals from antenna 1 and antenna 2 in order to obtain an output signalequivalent to that of a multiband antenna, and outputting a resultantcombined signal to a radio transceiver circuit.

In FIG. 5, in order to obtain an output signal equivalent to that of amultiband antenna, signals from antenna 1 (for example, inverted-F-typeantenna 1 according to conventional art 1) and antenna 2 (for example,slot antenna 2 according to conventional art 2) are input to a diplexerunit 7 through connector connection coaxial cables 51, 52 and connectors61, 62 respectively and combined therein, and the combined signal isoutput to a radio transceiver circuit through a connector connectioncoaxial cable 53 and a connector 63. If a divider is used instead ofdiplexer unit 7, loss is increased.

Antenna multiplexer circuit 8 as described above has the followingdisadvantages: (1) a plurality of antennas are necessary; (2) diplexerunit 7 or a divider is necessary; and (3) a plurality of coaxial cablesand connectors extending from an input of each antenna to an output ofthe radio transceiver circuit are necessary.

These factors cause significant cost increase and impose restriction ona dimension, a shape, design, or the like of the portable electronicapparatus due to a space for housing these components. In addition, ifantenna multiplexer circuit 8 as described above is used for adaption tobroader band, in order to combine directivity of the signal from antenna1 with directivity of the signal from antenna 2, directivity obtainedfrom the output signal from the multiplexer circuit is different fromthe directivity of the signal from antenna 1 and the directivity of thesignal from antenna 2. As a result, originally-intended directivity ofeach of the signal from antenna 1 and the signal from antenna 2 cannotbe obtained.

An object of the first invention is to provide a broad-band plateantenna suitable for a portable electronic apparatus, that can beadapted to broad band and multiband and can obtain originally-intendeddirectivity of a signal from an antenna without increase in cost andrestriction on a dimension, a shape, design, or the like of the portableelectronic apparatus due to a housing space.

The first invention is directed to an antenna 12 in which a plurality oflinear element portions and a slot element portion are integrally formed(hereinafter, referred to as broad-band plate antenna 12) developed bycombining an inverted-F-type antenna and a slot antenna according to theconventional art as shown in FIG. 8 as will be described later.

[Problems to be Solved by Second Invention]

When improvement in gain is aimed by forming the broad-band plateantenna in a shape suited to a condition for mount on a portableelectronic apparatus, as shown in FIG. 8 which will be described later,in some cases, a linear element portion 22 a (hereinafter, referred toas a first linear element portion) in a peripheral portion of theantenna is desirably made shorter than a linear element portion 22 b(hereinafter, referred to as a second linear element portion) located onan inner side of first linear element portion 22 a. In such a case,however, first linear element portion 22 a is less likely to be excited.

Now consider an antenna constituted of a 5 GHz band slot element, a 5GHz band linear element, and a 2.4 GHz band linear element. Here, firstlinear element portion 22 a has a length longer than second linearelement portion 22 b. In order for first linear element portion 22 a tobe more likely to be excited, the 5 GHz band slot element, the 5 GHzband linear element, and the 2.4 GHz band linear element having a lengthlonger than the 5 GHz band linear element are arranged in this orderfrom groundplate portion 21. Since influence by a housing or the likebecomes larger as the distance from the housing to each element portionis small, the influence is greatest on the 5 GHz band slot element,second greatest on the 5 GHz band linear element, and least on the 2.4GHz band linear element. That is, influence is locally exerted on the 5GHz band.

In order to address this problem, modification in arrangement, that is,arrangement in the order of the 5 GHz band slot element, the 2.4 GHzband linear element, and the 5 GHz band linear element may be possible.In this case, however, first linear element portion 22 a is shorter thansecond linear element portion 22 b.

As shown in FIG. 8 which will be described later, excitation of firstlinear element portion 22 a is carried out in the following manner.Initially, second linear element portion 22 b is excited. Along withthis excitation, electromagnetic field generated in a secondone-end-open gap portion 25 b serving as a non-conductive portion iscoupled from an opening portion of second one-end-open gap portion 25 bto an opening portion of a first one-end-open gap portion 25 a, togenerate electromagnetic field in first one-end-open gap portion 25 a,thereby exciting first linear element portion 22 a. If second linearelement portion 22 b is made longer, the opening portions are distantfrom each other. Then, coupling becomes weaker and first linear elementportion 22 a is less likely to be excited.

An object of the second invention is to provide a broad-band plateantenna capable of sufficiently exciting a first linear element portion30 a even if first linear element portion 30 a is shorter than a secondlinear element portion 30 b so that influence by a housing or the likeis not exerted locally on a specific frequency band, in addition toattaining an effect suitable for a portable electronic apparatus thatcan be adapted to both broad band and multiband and can obtaindirectivity of a signal from an antenna according to the firstinvention.

[Problems to be Solved by Third Invention]

An antenna having an unbalanced shape such as an inverted-F-type antennais generally formed by an element forming portion (plate antenna widtha×composite element portion length y1) and groundplate portion 21 (plateantenna width a×groundplate portion length y2). When an area of theelement forming portion is small, an area of an element portion (aconductive portion) or an area of a non-conductive portion or a gapportion becomes small. Then, an operation band where operation withnecessary reflection loss (return loss) is possible becomes narrower.

If a feeding point forming conductor portion 23 and a slotelement-groundplate short-circuiting portion 27 are present betweensecond linear element portion 30 b and groundplate portion 21 in FIG. 13according to the second invention which will be described later, theoperation band of second linear element portion 30 b becomes narrower.If feeding point forming conductor portion 23 and slotelement-groundplate short-circuiting portion 27 are removed, a slotelement portion 24 surrounded by these portions disappears.

Alternatively, a third linear element portion 30 c is newly provided.Third linear element portion 30 c has approximately half the length ofslot element portion 24, with respect to the same operation frequency.Therefore, a gap between second linear element portion 30 b andgroundplate portion 21 is increased, so that the operation band ofsecond linear element portion 30 b can be broadened.

As a result, a broad-band plate antenna 20 having a small compositeelement portion length y1 in FIG. 16 according to the third inventionwhich will be described later can be provided. Composite element portionlength y1 corresponds to composite element portion mount length z1 whenmounted on a notebook personal computer, and represents a portion thatcannot extend along LCD module 18 and housing (metal) 16 if radiation isto be performed. Therefore, if a dimension of these portions is madesmaller, a compact notebook personal computer can be provided.

An object of the third invention is to provide a broad-band plateantenna capable of sufficiently exciting first linear element portion 30a even if first linear element portion 30 a is shorter than secondlinear element portion 30 b so that influence by a housing or the likeis not exerted locally on a specific frequency band, in addition toattaining an effect suitable for a portable electronic apparatus thatcan be adapted to both broad band and multiband and can obtaindirectivity of a signal from an antenna according to the firstinvention, as well as achieving a broader operation band of secondlinear element portion 30 b by increasing an area of second linearelement portion 30 b and an area of a gap portion between second linearelement portion 30 b and groundplate portion 21 according to the secondinvention.

DISCLOSURE OF THE INVENTION

[Means for Solving Problems According to First Invention]

According to solving means of the first invention, as shown in FIG. 7,there is provided a broad-band plate antenna 11 in which a single linearelement portion and a slot element portion are integrally formed,wherein a one-end-open non-conductive surface 25 is provided in aconductive substrate 10 in parallel to a part of an outer perimeter ofconductive substrate 10, so as to form a linear element portion 22between the part of the outer perimeter and one-end-open non-conductivesurface 25,

a closed rectangle shaped non-conductive surface is provided inconductive substrate 10 in parallel to one-end-open non-conductivesurface 25, so as to form slot element portion 24,

a non-conductive portion 28 is provided in feeding point formingconductive portion 23 formed between one-end-open non-conductive surface25 and slot element portion 24, so as to use opposing ends ofnon-conductive portion 28 as a composite element feeding point 14, and

remaining conductive portion of conductive substrate 10 other thanlinear element portion 22, slot element portion 24, and feeding pointforming conductive portion 23 is used as groundplate portion 21.

[Means for Solving Problems According to Second Invention]

According to solving means of the second invention, as shown in FIG. 13,there is provided broad-band plate antenna 12, wherein a firstone-end-open non-conductive surface 25 a is provided in conductivesubstrate 10 in parallel to a part of an outer perimeter of conductivesubstrate 10, so as to form linear element portion 30 a (first linearelement portion 30 a) of which length on an outer peripheral side ofconductive substrate 10 is shorter between the part of the outerperimeter and first one-end-open non-conductive surface 25 a,

a second one-end-open non-conductive surface 25 b is provided inconductive substrate 10 in parallel to first one-end-open non-conductivesurface 25 a, so as to form linear element 30 b (second linear elementportion 30 b) having a length longer than first linear element portion30 a between second one-end-open non-conductive surface 25 b and firstone-end-open non-conductive surface 25 a,

a closed rectangle shaped non-conductive surface is provided inconductive substrate 10 in parallel to second one-end-opennon-conductive surface 25 b, so as to form slot element portion 24,

non-conductive portion 28 is provided in feeding point formingconductive portion 23 formed between second linear element portion 30 band slot element portion 24, so as to use opposing ends ofnon-conductive portion 28 as composite element feeding point 14,

first linear element portion 30 a and a feeding point forming conductorportion 23 are provided by a first conductor portion 31, and

remaining conductive substrate 10 other than the plurality of linearelement portions, slot element portion 24, and feeding point formingconductive portion 23 is used as groundplate portion 21.

[Means for Solving Problems According to Third Invention]

According to solving means of the third invention, as shown in FIG. 18,there is provided a broad-band plate antenna in which a plurality oflinear element portions are integrally formed according to the thirdinvention,

in the plate antenna including conductive substrate 10 forming acomposite element portion and groundplate portion 21,

first one-end-open non-conductive surface 25 a is provided in conductivesubstrate 10 in parallel to a part of an outer perimeter of conductivesubstrate 10, so as to form first linear element portion 30 a betweenthe part of the outer perimeter and first one-end-open non-conductivesurface 25 a,

a second one-end-open non-conductive surface 25 b to an Nth one-end-opennon-conductive surface 25 n are provided in conductive substrate 10 inparallel to first one-end-open non-conductive surface 25 a, so as toform second linear element portion 30 b to an Nth linear element portion30 n between second one-end-open non-conductive surface 25 b and an Nthone-end-open non-conductive surface 25 n, an (N−1)th linear elementportion 30 n-1 second closest to groundplate portion 21 has a lengthlonger than an (N−2)th linear element portion 30 n−2 third closest togroundplate portion 21 and Nth linear element portion 30 n closest togroundplate portion 21, an area of (N−1)th linear element portion 30 n−1is made larger in a direction of the (N−2)th linear element portion orin a direction of the Nth linear element portion or in the direction ofthe (N−2)th linear element portion and the direction of the Nth linearelement portion, and an area of a non-conductive portion between (N−1)thlinear element portion 30 n−1 and groundplate portion 21 is made larger,

a conductive portion commonly short-circuiting each element togroundplate portion 21 is identified as an each-element-groundplatecommonly short-circuiting conductive portion 26,

one feeding point 14 a is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of (N−1)th linear element portion 30 n−1,

the other feeding point 14 b is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of Nth linear element portion 30 n, and

an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of (N−2)th linear element portion30 n−2 and an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of Nth linear element portion 30n are connected to each other by first conductor portion 31.

All effects of the present invention described hereinafter do not needto be achieved at the same time, and one or more effect of the presentinvention should only be achieved.

[Effect of First Invention]

An effect of the first invention is as follows. According to abroad-band plate antenna in which a single linear element portion and aslot element portion are integrally formed, a portable electronicapparatus that can be adapted to both broad-band and multiband and canobtain originally-intended directivity of a signal from an antenna canbe realized without increase in cost and restriction on a dimension, ashape, design, or the like of the portable electronic apparatus due to ahousing space. Different operation frequencies are selected as theoperation frequency for the linear element portion and the operationfrequency for the slot element portion respectively, so that anelement-integrated antenna adapted to two operation frequency bands canbe obtained. In addition, adjacent operation frequencies are selected asthe operation frequency for the linear element portion and the operationfrequency for the slot element portion respectively, so that anelement-integrated antenna adapted to continuous and broad operationfrequency bands can be obtained.

[Effect of Second Invention]

An effect of the second invention is as follows. In addition to aneffect suitable for a portable electronic apparatus that can be adaptedto both broad-band and multiband and can obtain directivity of a signalfrom an antenna according to the first invention, an effect specific tothe second invention is that first linear element portion 30 a cansufficiently be excited even if first linear element portion 30 a isshorter than second linear element portion 30 b so that influence by ahousing or the like is not exerted locally on a specific frequency band.

[Effect of Third Invention]

An effect of the third invention is as follows. In addition to an effectsuitable for a portable electronic apparatus that can be adapted to bothbroad-band and multiband and can obtain directivity of a signal from anantenna according to the first invention, the third invention cansufficiently excite first linear element portion 30 a even if firstlinear element portion 30 a is shorter than second linear elementportion 30 b so that influence by a housing or the like is not exertedlocally on a specific frequency band. Moreover, an effect specific tothe third invention is that a broader operation band of the secondlinear element portion can be obtained by increasing an area of thesecond linear element portion and an area of a gap portion between thesecond linear element portion and the groundplate portion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an electrically equivalent diagram of a broad-band plateantenna in which a plurality of linear element portions are integrallyformed, wherein a second linear element portion has a length longer thana first linear element portion and a third linear element portion, anarea is made larger in a direction of the first linear element portion,and a composite element feeding point and a first conductor portion areprovided in the linear element portions.

FIG. 2 shows a notebook personal computer having an antenna attached,implemented by sandwiching a part of a groundplate portion of a plateantenna in a gap between a liquid crystal (LCD) module and a housing inan upper end portion of a display of the notebook personal computer andcovering the same with a plastic cover.

FIG. 3 is an electrically equivalent diagram of a plate inverted-F-typeantenna according to conventional art 1.

FIG. 4 is an electrically equivalent diagram of a slot antenna accordingto conventional art 2.

FIG. 5 is a diagram of an antenna multiplexer circuit combining signalsfrom antenna 1 and antenna 2 in order to obtain an output signalequivalent to that of a multiband antenna, and outputting a resultantcombined signal to a radio transceiver circuit.

FIGS. 6A to 6D are diagrams of feeding line connection showingconnection of a feeding line using a sperrtopf for connecting a singlefeeding line to a feeding point in the electrically equivalent diagramof the plate antenna according to the conventional art.

FIG. 7 is an electrically equivalent diagram of a broad-band plateantenna in which a single linear element portion and a slot elementportion are integrally formed according to the first invention.

FIG. 8 is an electrically equivalent diagram of a broad-band plateantenna in which a plurality of linear element portions and a slotelement portion are integrally formed, wherein the feeding pointaccording to the first invention is provided in aneach-element-groundplate commonly short-circuiting conductive portionand a feeding point forming conductor portion.

FIG. 9 is a first diagram of feeding line connection, in which a feedingline is connected to the feeding point of the broad-band plate antennain which a single linear element portion and a slot element portion areintegrally formed shown in FIG. 7.

FIG. 10 is a second diagram of feeding line connection, in which afeeding line is connected to the feeding point of the broad-band plateantenna in which a single linear element portion and a slot elementportion are integrally formed shown in FIG. 7.

FIGS. 11A and 11B are diagrams of feeding line connection in which afeeding line is connected to the feeding point of the broad-band plateantenna shown in FIG. 7 using a sperrtopf adapted to two operationfrequencies.

FIG. 12 illustrates a reflection property of the broad-band plateantenna in which a plurality of linear element portions and a slotelement portion are integrally formed according to the first inventionshown in FIG. 8.

FIG. 13 is an electrically equivalent diagram of the broad-band plateantenna in which a plurality of linear element portions and a slotelement portion are integrally formed according to the second invention,wherein the second linear element portion in the broad-band plateantenna in which a plurality of linear element portions and a slotelement portion are integrally formed according to the first inventionshown in FIG. 8 has a length longer than the first linear elementportion, and the feeding point is provided in a protruding portionformed at a connection portion of the each-element-groundplate commonlyshort-circuiting conductive portion and the second linear elementportion and in the feeding point forming conductor portion.

FIG. 14 is an electrically equivalent diagram of the broad-band plateantenna in which a plurality of linear element portions and a slotelement portion are integrally formed according to the second invention,wherein the second linear element portion according to the firstinvention shown in FIG. 8 has a length longer than the first linearelement portion, and the feeding point is provided in a protrudingportion of the each-element-groundplate commonly short-circuitingconductive portion and in the feeding point forming conductor portion.

FIG. 15 is an electrically equivalent diagram of the broad-band plateantenna in which a plurality of linear element portions and a slotelement portion are integrally formed according to the second invention,wherein the second linear element portion according to the firstinvention shown in FIG. 8 has a length longer than the first linearelement portion, and the feeding point according to the second inventionis provided in a protruding portion of the second linear element portionand in the feeding point forming conductor portion.

FIG. 16 is an electrically equivalent diagram of a broad-band plateantenna in which a plurality of linear element portions are integrallyformed according to the third invention, wherein a composite elementportion is formed by the first linear element portion to a third linearelement portion, the second linear element portion has a length longerthan the first linear element portion and the third linear elementportion, the feeding point is provided in the second linear elementportion and the third linear element portion, and a first conductorportion is connected to the first linear element portion and the thirdlinear element portion.

FIG. 17 is an electrically equivalent diagram of a broad-band plateantenna in which a plurality of linear element portions are integrallyformed according to the third invention, wherein a composite elementportion is formed by the first linear element portion to the thirdlinear element portion, the second linear element portion has a lengthlonger than the first linear element portion and the third linearelement portion, an area is made larger in a direction of the firstlinear element portion and in a direction of the third linear elementportion, the feeding point is provided in the second linear elementportion and the third linear element portion, and the first conductorportion is connected to the first linear element portion and the thirdlinear element portion.

FIG. 18 is an electrically equivalent diagram of a broad-band plateantenna in which a plurality of linear element portions are integrallyformed according to the third invention, wherein a composite elementportion is formed by the first linear element portion to an Nth linearelement portion, an (N−1)th linear element portion has a length longerthan an (N−2)th linear element portion and the Nth linear elementportion, an area is made larger (a) in a direction of the Nth linearelement portion, or (b) in a direction of the (N−2)th linear elementportion, or (c) in the direction of the Nth linear element portion andin the direction of the (N−2)th linear element portion, the feedingpoint is provided in the Nth linear element portion closest togroundplate portion 21 and in the (N−1)th linear element portion secondclosest to groundplate portion 21, and an area in the vicinity of theeach-element-groundplate commonly short-circuiting conductive portion ofthe (N−2)th linear element portion and an area in the vicinity of theeach-element-groundplate commonly short-circuiting conductive portion ofthe Nth linear element portion closest to groundplate portion 21 areconnected by the first conductor portion.

FIG. 19 illustrates a reflection property of the broad-band plateantenna in which a plurality of linear element portions are integrallyformed according to the third invention shown in FIG. 1.

BEST MODE FOR CARRYING OUT THE INVENTION

The best mode for carrying out the invention is realized by a broad-bandplate antenna in which a plurality of linear element portions areintegrally formed according to the third invention, wherein in thecomposite element portion formed by first linear element portion 30 a tothird linear element portion 30 c shown in FIG. 16 according to thethird invention, as shown in FIG. 1, the second linear element portionhas a length longer than first linear element portion 30 a and thirdlinear element portion 30 c, an area of the second linear elementportion and an area of a gap portion between the second linear elementportion and the groundplate portion is made larger in a direction offirst linear element portion 30 a, an area of second linear elementportion 30 b and an area of the gap portion between second linearelement portion 30 b and groundplate portion 21 are made larger, onefeeding point 14 a is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of a second linear element portion 30 d, the other feeding point 14 b isprovided in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of third linear element portion30 c, and an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of first linear element portion30 a and an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of third linear element portion30 c are connected by first conductor portion 31.

Embodiments Other Than Best Mode

In the following, embodiments for carrying out the invention of thesubject application other than the best mode for carrying out theinvention described above will be enumerated. The embodiments will bedescribed with reference to the drawings, and the drawings referred toin the embodiments will now be explained.

Description of the Drawings of Embodiments

FIG. 1 is an electrically equivalent diagram of a broad-band plateantenna in which a plurality of linear element portions are integrallyformed, wherein the second linear element portion has a length longerthan the first linear element portion and the third linear elementportion, an area of second linear element portion 30 b and a gap portionbetween second linear element portion 30 b and groundplate portion 21 ismade larger in a direction of the first linear element portion, and thecomposite element feeding point and the first conductor portion areprovided in the linear element portions.

FIG. 7 is an electrically equivalent diagram of the broad-band plateantenna in which a single linear element portion and a slot elementportion are integrally formed according to the first invention.

FIG. 8 is an electrically equivalent diagram of the broad-band plateantenna in which a plurality of linear element portions and a slotelement portion are integrally formed, wherein the feeding pointaccording to the first invention is provided in a protruding portion ofthe each-element-groundplate commonly short-circuiting conductiveportion and in the feeding point forming conductor portion.

FIG. 9 is a first diagram of coaxial feeding line connection, in which acoaxial feeding line is connected to the feeding point of the broad-bandplate antenna in which a single linear element portion and a slotelement portion are integrally formed shown in FIG. 7.

FIG. 10 is a second diagram of coaxial feeding line connection, in whicha coaxial feeding line is connected to the feeding point of thebroad-band plate antenna in which a single linear element portion and aslot element portion are integrally formed shown in FIG. 7.

FIGS. 11A and 11B are diagrams of coaxial feeding line connection, inwhich a coaxial feeding line is connected to the feeding point of thebroad-band plate antenna shown in FIG. 7 using a sperrtopf adapted totwo operation frequencies.

FIG. 12 illustrates a reflection property of the broad-band plateantenna in which a plurality of linear element portions and a slotelement portion are integrally formed according to the first inventionshown in FIG. 8.

FIG. 13 is an electrically equivalent diagram of a broad-band plateantenna in which a plurality of linear element portions and a slotelement portion are integrally formed according to the second invention,wherein the second linear element portion of the antenna according tothe first invention shown in FIG. 8 has a length longer than the firstlinear element portion, and the feeding point is provided in theprotruding portion formed at the connection portion of theeach-element-groundplate commonly short-circuiting conductive portionand the second linear element portion and in the feeding point formingconductor portion.

FIG. 14 is an electrically equivalent diagram of the broad-band plateantenna in which a plurality of linear element portions and a slotelement portion are integrally formed according to the second invention,wherein the second linear element portion of the antenna according tothe first invention shown in FIG. 8 has a length longer than the firstlinear element portion, and the feeding point is provided in theprotruding portion of the each-element-groundplate commonlyshort-circuiting conductive portion and in the feeding point formingconductor portion.

FIG. 15 is an electrically equivalent diagram of the broad-band plateantenna in which a plurality of linear element portions and a slotelement portion are integrally formed according to the second invention,wherein the second linear element portion of the antenna according tothe first invention shown in FIG. 8 has a length longer than the firstlinear element portion, and the feeding point according to the secondinvention is provided in the protruding portion of the second linearelement portion and in the feeding point forming conductor portion.

FIG. 16 is an electrically equivalent diagram of a broad-band plateantenna in which a plurality of linear element portions are integrallyformed according to the third invention, wherein the composite elementportion is formed by the first linear element portion to the thirdlinear element portion, the second linear element portion has a lengthlonger than the first linear element portion and the third linearelement portion, the feeding point is provided in the second linearelement portion and the third linear element portion, and the firstconductor portion is connected to the first linear element portion andthe third linear element portion.

FIG. 17 is an electrically equivalent diagram of a broad-band plateantenna in which a plurality of linear element portions are integrallyformed according to the third invention, wherein the composite elementportion is formed by the first linear element portion to the thirdlinear element portion, the second linear element portion has a lengthlonger than the first linear element portion and the third linearelement portion, an area is made larger in a direction of the firstlinear element portion and in a direction of the third linear elementportion, the feeding point is provided in the second linear elementportion and the third linear element portion, and the first conductorportion is connected to the first linear element portion and the thirdlinear element portion.

FIG. 18 is an electrically equivalent diagram of a broad-band plateantenna in which a plurality of linear element portions are integrallyformed according to the third invention, wherein the composite elementportion is formed by the first linear element portion to the Nth linearelement portion, (N−1)th linear element portion 30 n−1 has a lengthlonger than (N−2)th linear element portion 30 n−2 and Nth linear elementportion 30 n, an area of (N−1)th linear element portion 30 n−1 is madelarger (a) in a direction of (N−2)th linear element portion 30 n−2, or(b) in a direction of Nth linear element portion 30 n, or (c) in thedirection of (N−2)th linear element portion 30 n−2 and in the directionof Nth linear element portion 30 n, one feeding point 14 a is providedin Nth linear element portion 30 n closest to groundplate portion 21,the other feeding point 14 b is provided in (N−1)th linear elementportion 30 n-1 second closest to groundplate portion 21, and an area inthe vicinity of each-element-groundplate commonly short-circuitingconductive portion 26 of (N−2)th linear element portion 30 n−2 and anarea in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of Nth linear element portion 30n closest to groundplate portion 21 are connected by first conductorportion 31.

FIG. 19 illustrates a reflection property of the broad-band plateantenna in which a plurality of linear element portions are integrallyformed according to the third invention shown in FIG. 1. FIG. 19,similarly to FIG. 12 above, illustrates a reflection property, in whichthe abscissa represents an operation frequency [GHz] input/output to thefeeding point of broad-band plate antenna 20 in which a plurality oflinear element portions are integrally formed, while the ordinaterepresents reflection loss (return loss) [dB] specified by a shape of anantenna for each frequency.

In the following, specific examples obtained by modifying and expandingthe means for solving the problems will be shown as embodiments(hereinafter, referred to as an aspect) in a form of claims, withreference to the drawing and reference numerals therein.

[Aspect According to First Invention]

According to the invention in aspect 1, as shown in FIG. 7, there isprovided broad-band plate antenna 11 in which a single linear elementportion and a slot element portion are integrally formed, whereinone-end-open non-conductive surface 25 is provided in conductivesubstrate 10 in parallel to a part of the outer perimeter of conductivesubstrate 10, so as to form linear element portion 22 between the partof the outer perimeter and one-end-open non-conductive surface 25,

a closed rectangle shaped non-conductive surface is provided inconductive substrate 10 in parallel to one-end-open non-conductivesurface 25, so as to form slot element portion 24,

non-conductive portion 28 is provided in feeding point formingconductive portion 23 formed between one-end-open non-conductive surface25 and slot element portion 24, so as to use opposing ends ofnon-conductive portion 28 as composite element feeding point 14, and

remaining conductive portion of conductive substrate 10 other thanlinear element portion 22, slot element portion 24, and feeding pointforming conductive portion 23 is used as groundplate portion 21.

According to the invention in aspect 2, as shown in FIG. 7, there isprovided broad-band plate antenna 11 in which a single linear elementportion and a slot element portion are integrally formed, wherein

one-end-open gap portion 25 is provided in conductive substrate 10 inparallel to a part of an outer perimeter of conductive substrate 10, soas to form linear element portion 22 between the part of the outerperimeter and one-end-open gap portion 25,

a slot is provided in conductive substrate 10 in parallel toone-end-open gap portion 25, so as to form slot element portion 24,

opening portion 28 is provided in feeding point forming conductorportion 23 formed between one-end-open gap portion 25 and slot elementportion 24, so as to use opposing ends of opening portion 28 ascomposite element feeding point 14, and

remaining conductive substrate 10 other than linear element portion 22,slot element portion 24, and feeding point forming conductor portion 23is used as a groundplate portion 21.

[Effect of Aspect 1 and Aspect 2]

According to the broad-band plate antenna in which a single linearelement portion and a slot element portion are integrally formed recitedin aspects 1 and 2, a portable electronic apparatus that can be adaptedto broad-band and multiband and can obtain originally-intendeddirectivity of a signal from an antenna can be realized without increasein cost and restriction on a dimension, a shape, design, or the like ofthe portable electronic apparatus due to a housing space. Differentoperation frequencies are selected as the operation frequency for thelinear element portion and the operation frequency for the slot elementportion respectively, so that an element-integrated antenna adapted totwo operation frequency bands can be obtained. In addition, adjacentoperation frequencies are selected as the operation frequency for thelinear element portion and the operation frequency for the slot elementportion respectively, so that an element-integrated antenna adapted tocontinuous and broad operation frequency bands can be obtained.

According to the invention in aspect 3, as shown in FIG. 8, there isprovided broad-band plate antenna 12 in which a plurality of linearelement portions and a slot element portion are integrally formed,wherein

first one-end-open non-conductive surface 25 a is provided in conductivesubstrate 10 in parallel to a part of the outer perimeter of conductivesubstrate 10, so as to form first linear element portion 22 a betweenthe part of the outer perimeter and first one-end-open non-conductivesurface 25 a,

second one-end-open non-conductive surface 25 b is provided inconductive substrate 10 in parallel to first one-end-open non-conductivesurface 25 a, so as to form second linear element portion 22 b betweensecond one-end-open non-conductive surface 25 b and first one-end-opennon-conductive surface 25 a,

a closed rectangle shaped non-conductive surface is provided inconductive substrate 10 in parallel to second one-end-opennon-conductive surface 25 b, so as to form slot element portion 24,

non-conductive portion 28 is provided in feeding point formingconductive portion 23 formed between second linear element portion 22 band slot element portion 24, so as to use opposing ends ofnon-conductive portion 28 as composite element feeding point 14, and

remaining conductive substrate 10 other than the plurality of linearelement portions, slot element portion 24, and feeding point formingconductive portion 23 is used as groundplate portion 21.

According to the invention in aspect 4, as shown in FIG. 8, there isprovided broad-band plate antenna 12 in which a plurality of linearelement portions and a slot element portion are integrally formed,wherein

first one-end-open gap portion 25 a is provided in conductive substrate10 in parallel to a part of the outer perimeter of conductive substrate10, so as to form first linear element portion 22 a between the part ofthe outer perimeter and first one-end-open gap portion 25 a,

second one-end-open gap portion 25 b is provided in conductive substrate10 in parallel to first one-end-open gap portion 25 a, so as to formsecond linear element portion 22 b between second one-end-open gapportion 25 b and first one-end-open gap portion 25 a,

a slot is provided in conductive substrate 10 in parallel to secondone-end-open gap portion 25 b, so as to form slot element portion 24,

opening portion 28 is provided in feeding point forming conductorportion 23 formed between second linear element portion 22 b and slotelement portion 24, so as to use opposing ends of opening portion 28 ascomposite element feeding point 14, and

remaining conductive substrate 10 other than the plurality of linearelement portions, slot element portion 24, and feeding point formingconductor portion 23 is used as groundplate portion 21.

[Effect of Aspect 3 and Aspect 4]

According to the broad-band plate antenna in which a plurality of linearelement portions and a slot element portion are integrally formedrecited in aspects 3 and 4, a portable electronic apparatus that can beadapted to further broader band and multiband can be realized, ascompared with that recited in aspects 1 and 2. Different operationfrequencies are selected as the operation frequency for the first linearelement portion, the operation frequency for the second linear elementportion, and the operation frequency for the slot element portionrespectively, so that an element-integrated antenna adapted to threeoperation frequency bands can be obtained. In addition, adjacentoperation frequencies are selected as the operation frequency for thefirst linear element portion, the operation frequency for the secondlinear element portion, and the operation frequency for the slot elementportion respectively, so that an element-integrated antenna adapted tocontinuous and broad operation frequency bands can be obtained.

According to the invention recited in aspect 5, there is provided abroad-band plate antenna in which a plurality of linear element portionsand a slot element portion are integrally formed, wherein

first one-end-open non-conductive surface 25 a is provided in conductivesubstrate 10 in parallel to a part of the outer perimeter of conductivesubstrate 10, so as to form first linear element portion 22 a betweenthe part of the outer perimeter and first one-end-open non-conductivesurface 25 a,

a plurality of one-end-open non-conductive surfaces consisting of secondone-end-open non-conductive surface 25 b to Nth one-end-opennon-conductive surface 25 n are provided in conductive substrate 10 inparallel to first one-end-open non-conductive surface 25 a, so as toform a plurality of linear element portions consisting of second linearelement portion 22 b to Nth linear element portion 22 n betweenone-end-open non-conductive surfaces,

a closed rectangle shaped non-conductive surface is provided inconductive substrate 10 in parallel to Nth one-end-open non-conductivesurface 25 n, so as to form slot element portion 24,

non-conductive portion 28 is provided in feeding point formingconductive portion 23 formed between Nth one-end-open non-conductivesurface 25 n and slot element portion 24, so as to use opposing ends ofnon-conductive portion 28 as composite element feeding point 14, and

remaining conductive substrate 10 other than the plurality of linearelement portions, slot element portion 24, and feeding point formingconductive portion 23 is used as groundplate portion 21.

According to the invention recited in aspect 6, as shown in FIG. 11A,there is provided a broad-band plate antenna, wherein a firstcylindrical conductor 19 a having a length corresponding to ¼ wavelengthof a first operation frequency out of two operation frequencies isdisposed on an outer circumference of an external conductor 5 b of acoaxial cable, a second cylindrical conductor 19 b having a lengthcorresponding to ¼ wavelength of a second operation frequency out of twooperation frequencies is disposed on an outer circumference of firstcylindrical conductor 19 a, and sperrtopf 19 adapted to two operationfrequencies and short-circuiting first cylindrical conductor 19 a andsecond cylindrical conductor 19 b to external conductor 5 b of thecoaxial cable is connected to composite element feeding point 14 recitedin aspects 1 to 5 according to the first invention.

[Aspect According to Second Invention]

According to the invention recited in aspect 7, as shown in FIG. 13,there is provided broad-band plate antenna 12, wherein firstone-end-open non-conductive surface 25 a is provided in conductivesubstrate 10 in parallel to a part of the outer perimeter of conductivesubstrate 10, so as to form first linear element portion 30 a of whichlength on an outer peripheral side of conductive substrate 10 is shorterbetween the part of the outer perimeter and first one-end-opennon-conductive surface 25 a,

second one-end-open non-conductive surface 25 b is provided inconductive substrate 10 in parallel to first one-end-open non-conductivesurface 25 a, so as to form second linear element portion 30 b having alength longer than first linear element portion 30 a between secondone-end-open non-conductive surface 25 b and first one-end-opennon-conductive surface 25 a,

a closed rectangle shaped non-conductive surface is provided inconductive substrate 10 in parallel to second one-end-opennon-conductive surface 25 b, so as to form slot element portion 24,

non-conductive portion 28 is provided in feeding point formingconductive portion 23 formed between second linear element portion 30 band slot element portion 24, so as to use opposing ends ofnon-conductive portion 28 as composite element feeding point 14,

first linear element portion 30 a and feeding point forming conductorportion 23 are connected to each other by first conductor portion 31,and

remaining conductive substrate 10 other than the plurality of linearelement portions, slot element portion 24, and feeding point formingconductive portion 23 is used as groundplate portion 21.

According to the invention recited in aspect 8, as shown in FIG. 13,there is provided broad-band plate antenna 12 in which a plurality oflinear element portions and a slot element portion are integrallyformed, wherein

first one-end-open gap portion 25 a is provided in conductive substrate10 in parallel to a part of an outer perimeter of conductive substrate10, so as to form first linear element portion 30 a between the part ofthe outer perimeter and first one-end-* open gap portion 25 a,

second one-end-open gap portion 25 b is provided in conductive substrate10 in parallel to first one-end-open gap portion 25 a, so as to formsecond linear element portion 30 b having a length longer than firstlinear element portion 30 a between second one-end-open gap portion 25 band first one-end-open gap portion 25 a,

a slot is provided in conductive substrate 10 in parallel to secondone-end-open gap portion 25 b, so as to form slot element portion 24,

opening portion 28 is provided in feeding point forming conductorportion 23 formed between second linear element portion 30 b and slotelement portion 24, so as to use opposing ends of opening portion 28 ascomposite element feeding point 14,

first linear element portion 30 a and feeding point forming conductorportion 23 are connected to each other by first conductor portion 31,and

remaining conductive substrate 10 other than the plurality of linearelement portions, slot element portion 24, and feeding point formingconductor portion 23 is used as groundplate portion 21.

According to the invention recited in aspect 9, there is provided abroad-band plate antenna, wherein

first one-end-open non-conductive surface 25 a is provided in conductivesubstrate 10 in parallel to a part of the outer perimeter of conductivesubstrate 10, so as to form first linear element portion 30 a betweenthe part of the outer perimeter and first one-end-open non-conductivesurface 25 a,

a plurality of one-end-open non-conductive surfaces consisting of secondone-end-open non-conductive surface 25 b to Nth one-end-opennon-conductive surface 25 n are provided in conductive substrate 10 inparallel to first one-end-open non-conductive surface 25 a, so as toform a plurality of linear element portions consisting of second linearelement portion 30 b having a length longer than first linear elementportion 30 a to Nth linear element portion 22 n between one-end-opennon-conductive surfaces,

a closed rectangle shaped non-conductive surface is provided inconductive substrate 10 in parallel to Nth one-end-open non-conductivesurface 25 n, so as to form slot element portion 24,

non-conductive portion 28 is provided in feeding point formingconductive portion 23 formed between Nth one-end-open non-conductivesurface 25 n and slot element portion 24, so as to use opposing ends ofnon-conductive portion 28 as composite element feeding point 14,

N−1th linear element portion 30 n−1 and feeding point forming conductorportion 23 are connected to each other by first conductor portion 31,and

remaining conductive substrate 10 other than the plurality of linearelement portions, slot element portion 24, and feeding point formingconductive portion 23 is used as groundplate portion 21.

According to the invention recited in aspect 10, in FIG. 13, there isprovided a broad-band plate antenna in which feeding point 14 b of thesecond linear element portion is provided in a protruding portion formedat a connection portion of each-element-groundplate commonlyshort-circuiting conductive portion 26 and second linear element portion30 b (a second conductor portion 32 a protruding from theelement-groundplate short-circuiting connection portion) and feedingpoint forming conductor portion 23, and one feeding point 14 a isprovided in feeding point forming conductor portion 23.

According to the invention recited in aspect 11, in FIG. 14, there isprovided a broad-band plate antenna in which feeding point 14 b of thesecond linear element portion is provided in a protruding portion ofeach-element-groundplate commonly short-circuiting conductive portion 26(a second conductor portion 32 b protruding from theeach-element-groundplate commonly short-circuiting conductive portion),and one feeding point 14 a is provided in feeding point formingconductor portion 23.

According to the invention recited in aspect 12, in FIG. 15, there isprovided a broad-band plate antenna in which feeding point 14 b of thesecond linear element portion (the other feeding point 14 b) is providedin a protruding portion of second linear element portion 30 b (a secondconductor portion 32 c protruding from the second element portion), andone feeding point 14 a is provided in feeding point forming conductorportion 23.

[Aspect According to Third Invention]

According to the invention recited in aspect 13, there is provided abroad-band plate antenna in which a plurality of linear element portionsare integrally formed according to the third invention, wherein acomposite element portion is formed by first linear element portion 30 ato third linear element portion 30 c, second linear element portion 30 bhas a length longer than first linear element portion 30 a, an area ofsecond linear element portion 30 b and an area of a non-conductivesurface between second linear element portion 30 b and groundplateportion 21 are made larger by (a) expansion in a direction of firstlinear element portion 30 a, or (b) by expansion in a direction of thirdlinear element portion 30 c, or (c) by expansion in the direction offirst linear element portion 30 a and third linear element portion 30 cand by making third linear element portion 30 c shorter than secondlinear element portion 30 b,

a conductive portion commonly short-circuiting each element togroundplate portion 21 is identified as each-element-groundplatecommonly short-circuiting conductive portion 26, one feeding point 14 ais provided in second linear element portion 30 b, the other feedingpoint 14 b is provided in third linear element portion 30 c, and an areain the vicinity of each-element-groundplate commonly short-circuitingconductive portion 26 of first linear element portion 30 a and an areain the vicinity of each-element-groundplate commonly short-circuitingconductive portion 26 of third linear element portion 30 c are connectedto each other by first conductor portion 31.

According to the invention recited in aspect 14, in FIG. 16, there isprovided a broad-band plate antenna in which a plurality of linearelement portions are integrally formed according to the third invention,wherein a composite element portion is formed by first linear elementportion 30 a to third linear element portion 30 c, second linear elementportion 30 b has a length longer than first linear element portion 30 a,third linear element portion 30 c has a length shorter than secondlinear element portion 30 b, an area of a non-conductive surface betweensecond linear element portion 30 b and groundplate portion 21 is madelarger, a conductive portion commonly short-circuiting each element togroundplate portion 21 is identified as each-element-groundplatecommonly short-circuiting conductive portion 26, one feeding point 14 ais provided in second linear element portion 30 b, the other feedingpoint 14 b is provided in third linear element portion 30 c, and an areain the vicinity of each-element-groundplate commonly short-circuitingconductive portion 26 of first linear element portion 30 a and an areain the vicinity of each-element-groundplate commonly short-circuitingconductive portion 26 of third linear element portion 30 c are connectedto each other by first conductor portion 31.

According to the invention recited in aspect 15, in FIG. 1, there isprovided a broad-band plate antenna in which a plurality of linearelement portions are integrally formed according to the third invention,wherein a composite element portion is formed by first linear elementportion 30 a to third linear element portion 30 c, second linear elementportion 30 b has a length longer than first linear element portion 30 a,an area of second linear element portion 30 b is made larger in adirection of first linear element portion 30 a, third linear elementportion 30 c has a length shorter than second linear element portion 30b, an area of a non-conductive surface between second linear elementportion 30 b and groundplate portion 21 is made larger, a conductiveportion commonly short-circuiting each element to groundplate portion 21is identified as each-element-groundplate commonly short-circuitingconductive portion 26, one feeding point 14 a is provided in secondlinear element portion 30 b, the other feeding point 14 b is provided inthird linear element portion 30 c, and an area in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of first linear element portion 30 a and an area in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of third linear element portion 30 c are connected to each other byfirst conductor portion 31.

According to the invention recited in aspect 16, in FIG. 17, there isprovided a broad-band plate antenna in which a plurality of linearelement portions are integrally formed according to the third invention,wherein a composite element portion is formed by first linear elementportion 30 a to third linear element portion 30 c, second linear elementportion 30 b has a length longer than first linear element portion 30 a,an area of second linear element portion 30 b is made larger in adirection of first linear element portion 30 a and third linear elementportion 30 c, third linear element portion 30 c has a length shorterthan second linear element portion 30 b, an area of a non-conductivesurface between second linear element portion 30 b and groundplateportion 21 is made larger, a conductive portion commonlyshort-circuiting each element to groundplate portion 21 is identified aseach-element-groundplate commonly short-circuiting conductive portion26, one feeding point 14 a is provided in second linear element portion30 b, the other feeding point 14 b is provided in third linear elementportion 30 c, and an area in the vicinity of each-element-groundplatecommonly short-circuiting conductive portion 26 of first linear elementportion 30 a and an area in the vicinity of each-element-groundplatecommonly short-circuiting conductive portion 26 of third linear elementportion 30 c are connected to each other by first conductor portion 31.

According to the invention recited in aspect 17, as shown in FIG. 18,there is provided a broad-band plate antenna including conductivesubstrate 10 forming the composite element portion and groundplateportion 21, wherein

first one-end-open non-conductive surface 25 a is provided in conductivesubstrate 10 in parallel to a part of the outer perimeter of conductivesubstrate 10, so as to form first linear element portion 30 a betweenthe part of the outer perimeter and first one-end-open non-conductivesurface 25 a,

second one-end-open non-conductive surface 25 b to Nth one-end-opennon-conductive surface 25 n are provided in conductive substrate 10 inparallel to first one-end-open non-conductive surface 25 a, so as toform second linear element portion 30 b to Nth linear element portion 30n between second one-end-open non-conductive surface 25 b and Nthone-end-open non-conductive surface 25 n, (N−1)th linear element portion30 n-1 second closest to groundplate portion 21 has a length longer than(N−2)th linear element portion 30 n−2 third closest to groundplateportion 21 and Nth linear element portion 30 n closest to groundplateportion 21, an area of (N−1)th linear element portion 30 n−1 is madelarger in a direction of the (N−2)th linear element portion or in adirection of the Nth linear element portion or in the direction of the(N−2)th linear element portion and the Nth linear element portion, andan area of a non-conductive portion between (N−1)th linear elementportion 30 n−1 and groundplate portion 21 is made larger,

a conductive portion commonly short-circuiting each element togroundplate portion 21 is identified as each-element-groundplatecommonly short-circuiting conductive portion 26,

one feeding point 14 a is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of (N−1)th linear element portion 30 n−1,

the other feeding point 14 b is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of Nth linear element portion 30 n, and

an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of (N−2)th linear element portion30 n−2 and an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of Nth linear element portion 30n are connected to each other by first conductor portion 31.

The plate antenna commonly implemented according to aspects 1 to 17described above and enhancing the effect obtained from each aspect is asfollows.

(1) The broad-band plate antenna in which the feeding point is connectedto an internal conductor and an external conductor of a coaxial cable.

(2) The broad-band plate antenna in which the feeding point is connectedto an internal conductor and an external conductor of a coaxial cable towhich a sperrtopf is applied.

(3) The broad-band plate antenna having a sperrtopf adapted to twooperation frequencies, in which a first cylindrical conductor having alength corresponding to ¼ wavelength of a first operation frequency outof two operation frequencies is disposed on an outer circumference of anexternal conductor of the coaxial cable, a second cylindrical conductorhaving a length corresponding to ¼ wavelength of a second operationfrequency out of two operation frequencies is disposed outside the firstcylindrical conductor, and the sperrtopf short-circuits the firstcylindrical conductor and the second cylindrical conductor to theexternal conductor of the coaxial cable.

EXAMPLE Example 1 According to First Invention

In the following, a structure of the example according to the firstinvention will be described with reference to the drawings. Example 1according to the first invention represents a broad-band plate antennain which a single linear element portion and a slot element portion areintegrally formed. FIG. 7 is an electrically equivalent diagram of thebroad-band plate antenna in which a single linear element portion and aslot element portion are integrally formed according to the firstinvention.

Broad-band plate antenna 11 in which a single linear element portion anda slot element portion are integrally formed shown in FIG. 7 isstructured in the following manner.

(1) One-end-open non-conductive surface 25 is provided in conductivesubstrate 10 in parallel to a part of the outer perimeter of conductivesubstrate 10, so as to form linear element portion 22 between the partof the outer perimeter and one-end-open non-conductive surface 25,

(2) a closed rectangle shaped non-conductive surface is provided inconductive substrate 10 in parallel to one-end-open non-conductivesurface 25, so as to form slot element portion 24,

(3) non-conductive portion 28 is provided in feeding point formingconductive portion 23 formed between one-end-open non-conductive surface25 and slot element portion 24, so as to use opposing ends ofnon-conductive portion 28 as composite element feeding point 14, and

(4) remaining conductive portion of conductive substrate 10 other thanlinear element portion 22, slot element portion 24, and feeding pointforming conductive portion 23 is used as groundplate portion 21.

In the structure described above, one-end-open non-conductive surface 25or slot element portion 24 may be formed by cutting and removing theconductor, or alternatively, the non-conductive surface may be formed byetching away the conductive surface of conductive substrate 10 or by notcoating a conductive-film-coat-substrate with a conductive film when itis fabricated.

Antenna 11 in which a single linear element portion and a slot elementportion are integrally formed, wherein one-end-open gap portion 25 orslot element portion 24 is formed by using a conductor for conductivesubstrate 10 and cutting and removing the conductor, is structured inthe following manner.

(1) One-end-open gap portion 25 is provided in conductive substrate 10in parallel to a part of the outer perimeter of conductive substrate 10,so as to form linear element portion 22 between the part of the outerperimeter and one-end-open gap portion 25,

(2) a slot is provided in conductive substrate 10 in parallel toone-end-open gap portion 25, so as to form slot element portion 24,

(3) opening portion 28 is provided in feeding point forming conductorportion 23 formed between one-end-open gap portion 25 and slot elementportion 24, so as to use opposing ends of opening portion 28 ascomposite element feeding point 14, and

(4) remaining conductive substrate 10 other than linear element portion22, slot element portion 24, and feeding point forming conductor portion23 is used as groundplate portion 21.

Example 2 According to First Invention

Example 2 according to the first invention represents the broad-bandplate antenna in which a plurality of linear element portions and a slotelement portion are integrally formed, wherein two linear elementportions in Example 1 are provided. FIG. 8 electrically illustrates thebroad-band plate antenna in which a plurality of linear element portionsand a slot element portion are integrally formed according to the firstinvention.

Antenna 12 in which a plurality of linear element portions and a slotelement portion are integrally formed shown in FIG. 8 is structured inthe following manner.

(1) First one-end-open non-conductive surface 25 a is provided inconductive substrate 10 in parallel to a part of the outer perimeter ofconductive substrate 10, so as to form first linear element portion 22 abetween the part of the outer perimeter and first one-end-opennon-conductive surface 25 a,

(2) second one-end-open non-conductive surface 25 b is provided inconductive substrate 10 in parallel to first one-end-open non-conductivesurface 25 a, so as to form second linear element portion 22 b betweensecond one-end-open non-conductive surface 25 b and first one-end-opennon-conductive surface 25 a,

(3) a closed rectangle shaped non-conductive surface is provided inconductive substrate 10 in parallel to second one-end-opennon-conductive surface 25 b, so as to form slot element portion 24,

(4) non-conductive portion 28 is provided in feeding point formingconductive portion 23 formed between second linear element portion 22 band slot element portion 24, so as to use opposing ends ofnon-conductive portion 28 as composite element feeding point 14, and

(5) remaining conductive substrate 10 other than the two linear elementportions, slot element portion 24, and feeding point forming conductiveportion 23 is used as groundplate portion 21.

Antenna 12 in which a plurality of linear element portions and a slotelement portion are integrally formed, wherein one-end-open gap portion25 or slot element portion 24 is formed by using a conductor forconductive substrate 10 and cutting and removing the conductor, isstructured in the following manner.

(1) First one-end-open gap portion 25 a is provided in conductivesubstrate 10 in parallel to a part of the outer perimeter of conductivesubstrate 10, so as to form first linear element portion 22 a betweenthe part of the outer perimeter and first one-end-open gap portion 25 a,

(2) second one-end-open gap portion 25 b is provided in conductivesubstrate 10 in parallel to first one-end-open gap portion 25 a, so asto form second linear element portion 22 b between second one-end-opengap portion 25 b and first one-end-open gap portion 25 a,

(3) a slot is provided in conductive substrate 10 in parallel to secondone-end-open gap portion 25 b, so as to form slot element portion 24,

(4) opening portion 28 is provided in feeding point forming conductorportion 23 formed between second linear element portion 22 b and slotelement portion 24, so as to use opposing ends of opening portion 28 ascomposite element feeding point 14, and

(5) remaining conductive substrate 10 other than the two linear elementportions, slot element portion 24, and feeding point forming conductorportion 23 is used as groundplate portion 21.

Example 3 According to First Invention

Not-shown Example 3 according to the first invention represents thebroad-band plate antenna in which a plurality of linear element portionsand a slot element portion are integrally formed, wherein two linearelement portions in Example 2 are replaced with three or more linearelement portions. As this plate antenna is similar to that in Example 2,description thereof will not be provided.

In the first invention including Examples 1 to 3 described above,examples of antenna 11 in which a single linear element portion and aslot element portion are integrally formed shown in FIG. 7, antenna 12in which two linear element portions and a slot element portion areintegrally formed shown in FIG. 8, and the antenna in which a pluralityof linear element portions and a slot element portion are integrallyformed are susceptible to various modifications. The outer perimeter ofconductive substrate 10 refers to an outer perimeter of the conductorbefore the conductor is worked, i.e., cut and removed. Normally, itsshape is rectangular or square, however, in addition to straightperimeter, the outer perimeter may partially or entirely be curved. Apart of the outer perimeter of conductive substrate 10 normallyrepresents one side of four sides of a rectangle or a square, however,it may be a part of the outer perimeter including a curve.

Plate inverted-F-type antenna 1 which is a modification of what iscalled a monopole antenna is formed by linear element portion 22 orgroundplate portion 21, or first linear element portion 22 a, secondlinear element portion 22 b, and groundplate portion 21, so that both ofthe linear element portion and slot element portion 24 cansimultaneously be excited. The linear element portion and slot elementportion 24 function at different operation frequency bands.

In the example shown in FIG. 7, antenna 11 in which a single linearelement portion and a slot element portion are integrally formed isassumed to have a rectangular shape, and its dimension is assumed asfollows. Specifically, a: a length in a direction in parallel to thelinear element portion and the slot element portion of conductivesubstrate 10; b: a length in a direction orthogonal to the linearelement portion and the slot element portion of conductive substrate 10;c: a width of one-end-open gap portion 25: d: a length of linear elementportion 22; e: a width of linear element portion 22; f: a width ofeach-element-groundplate commonly short-circuiting conductive portion26; g: a length of slot element portion 24; h: a width of feeding pointforming conductor portion 23; i: a width of slot element portion 24; j:a width of a slot element-groundplate short-circuiting portion 27; k: alength of opening portion 28; y1: a length of the composite elementportion; and y2: a length of the groundplate portion.

In antenna 11 in which a single linear element portion and a slotelement portion are integrally formed described above, length d oflinear element portion 22 is odd multiple of approximately ¼ wavelengthof the operation frequency. Length g of slot element portion 24 isinteger multiple of approximately ½ wavelength of the operationfrequency. Different operation frequencies are selected as the operationfrequency for linear element portion 22 and the operation frequency forslot element portion 24 respectively, so that an element-integratedantenna adapted to two operation frequency bands can be obtained. Inaddition, adjacent operation frequencies are selected as the operationfrequency for linear element portion 22 and the operation frequency forslot element portion 24 respectively, so that an element-integratedantenna adapted to continuous and broad operation frequency bands can beobtained.

In the example shown in FIG. 8, antenna 12 in which a plurality oflinear element portions and a slot element portion are integrally formedis assumed to have a rectangular shape, and a dimension not used inelement-integrated antenna 11 is assumed as follows: c1: a width offirst one-end-open gap portion 25 a; c2: a width of second one-end-opengap portion 25 b; d1: a length of first linear element portion 22 a; d2:a length of second linear element portion 22 b; e1: a width of firstlinear element portion 22 a; e2: a width of second linear elementportion 22 b; y1; a length of the composite element portion; and y2: alength of groundplate portion.

In broad-band plate antenna 12 in which a plurality of linear elementportions and a slot element portion are integrally formed describedabove as well, length d1 of first linear element portion 22 a and lengthd2 of second linear element portion 22 b are odd multiple ofapproximately ¼ wavelength of the operation frequency. Length g of slotelement portion 24 is integer multiple of approximately ½ wavelength ofthe operation frequency. Different operation frequencies are selected asthe operation frequency for first linear element portion 22 a, theoperation frequency for second linear element portion 22 b and theoperation frequency for slot element portion 24 respectively, so that anelement-integrated antenna adapted to three operation frequency bandscan be obtained. In addition, adjacent operation frequencies areselected as the operation frequency for first linear element portion 22a, the operation frequency for second linear element portion 22 b andthe operation frequency for slot element portion 24 respectively, sothat an element-integrated antenna adapted to continuous and broadoperation frequency bands can be obtained.

FIG. 9 is a first diagram of feeding line connection, in which a feedingline is connected to the feeding point of the broad-band plate antennain which a single linear element portion and a slot element portion areintegrally formed according to the first invention shown in FIG. 7. InFIG. 9, one feeding point 14 a (a soldered portion 14 a of internalconductor 5 a) of composite element feeding point 14 of opening portion28 of feeding point forming conductor portion 23 is connected tointernal conductor 5 a of the coaxial cable, and the other feeding point14 b (a soldered portion 14 b of external conductor 5 b) is connected toexternal conductor 5 b of the coaxial cable. The other end of coaxialcable 5 is connected to a not-shown radio transceiver circuit.

FIG. 10 is a second diagram of feeding line connection, in which afeeding line is connected to the feeding point of the broad-band plateantenna in which a single linear element portion and a slot elementportion are integrally formed according to the first invention shown inFIG. 7. As in FIG. 9, coaxial cable 5 is connected to composite elementfeeding point 14 and the radio transceiver circuit.

FIG. 6D is a diagram of feeding line connection, in which a feeding lineis connected to the feeding point in the electrically equivalent diagramof the plate antenna according to the conventional art by using thesperrtopf for connecting a single feeding line. Sperrtopf 9 refers to acylindrical conductor for preventing unnecessary current generated onthe outer surface of external conductor 5 b from a point where externalconductor 5 b of coaxial cable 5 is provided at feeding point 4 alongexternal conductor 5 b. FIG. 6A shows appearance when the sperrtopf isattached to the coaxial cable, FIG. 6B illustrates a structure, and FIG.6C shows a cross-sectional view.

FIG. 11A is a diagram of feeding line connection, in which a feedingline is connected to the feeding point of the broad-band plate antennaaccording to the first invention shown in FIG. 7 by using the sperrtopfadapted to two operation frequencies.

Sperrtopf 19 adapted to two operation frequencies shown in FIG. 1I Brefers to a cylindrical conductor for preventing unnecessary currentgenerated on the outer surface of external conductor 5 b from a pointwhere external conductor 5 b of coaxial cable 5 is connected to feedingpoint 14 b along external conductor 5 b, wherein first cylindricalconductor 19 a having a length corresponding to ¼ wavelength of a firstoperation frequency out of two operation frequencies is disposed on theouter circumference of external conductor 5 b of the coaxial cable,second cylindrical conductor 19 b having a length corresponding to ¼wavelength of a second operation frequency out of two operationfrequencies is disposed on the outer circumference of first cylindricalconductor 19 a, and the sperrtopf connects first cylindrical conductor19 a and second cylindrical conductor 19 b to external conductor 5 b ofthe coaxial cable.

FIG. 11B has shown the sperrtopf adapted to two operation frequenciesprovided at the feeding point in the electrically equivalent diagram ofthe broad-band plate antenna in which a single linear element portionand a slot element portion are integrally formed according to the firstinvention shown in FIG. 7. In the sperrtopf adapted to three operationfrequencies at the feeding point in the electrically equivalent diagramof the broad-band plate antenna in which a plurality of linear elementportions and a slot element portion are integrally formed according tothe first invention shown in FIG. 8, however, a third cylindricalconductor may be provided in addition to first cylindrical conductor 19a and second cylindrical conductor 19 b, and these three cylindricalconductors may be coaxially superposed and each connected to externalconductor 5 b of the coaxial cable.

FIG. 12 illustrates a reflection property of broad-band plate antenna 12in which a plurality of linear element portions and a slot elementportion are integrally formed according to the first invention shown inFIG. 8. FIG. 12 illustrates a reflection property, in which the abscissarepresents an operation frequency [GHz] input/output to the feedingpoint of the broad-band plate antenna in which a plurality of linearelement portions and a slot element portion are integrally formed, whilethe ordinate represents reflection loss (return loss) [dB] specified bya shape of an antenna for each frequency. In FIG. 12, a solid line Srepresents a reflection property of broad-band plate antenna 12 in whicha plurality of linear element portions and a slot element portion areintegrally formed according to the first invention shown in FIG. 8.

FIG. 12 compares, in dotted lines, (a) reflection property Ra when adimension of linear element portion 1 b of inverted-F-type antenna 1according to conventional art 1 shown in FIG. 3 is adapted to adimension of first linear element portion 22 a of the element-integratedantenna according to the first invention, (b) reflection property Rbwhen a dimension of linear element portion 1 b of plate inverted-F-typeantenna 1 according to conventional art 1 is adapted to a dimension ofsecond linear element portion 22 b of the element-integrated antennaaccording to the first invention, and (c) reflection property Rc when adimension of slot antenna slot opening portion 2 b according toconventional art 2 shown in FIG. 4 is adapted to a dimension of slotelement portion 24 of the element-integrated antenna according to thefirst invention.

A section of property Sbc shown in FIG. 12 represents the propertyobtained by contribution mainly of second linear element portion 22 band slot element portion 24 of the element-integrated antenna in FIG. 8.The operation frequencies are brought closer to each other, so that thefrequency band in which reflection loss is lower than allowable levelcan considerably be broader than the total of individual frequency bandsexhibiting properties Rb and Rc of the antenna according to theconventional art, as shown in FIG. 12.

Example 4 According to Second Invention

FIG. 13 shows Example 4 according to the second invention. FIG. 13 is anelectrically equivalent diagram of the broad-band plate antenna in whicha plurality of linear element portions and a slot element portion areintegrally formed, wherein opening portion 28 is provided in feedingpoint forming conductor portion 23 so that a protruding portion isformed at a connection portion of each-element-groundplate commonlyshort-circuiting conductive portion 26 and second linear element portion30 b (second conductor portion 32 a protruding from theelement-groundplate short-circuiting connection portion), the otherfeeding point 14 b is provided in second conductor portion 32 aprotruding from the element-groundplate short-circuiting connectionportion, and one feeding point 14 a is provided in feeding point formingconductor portion 23.

Broad-band plate antenna 12 shown in FIG. 13 is structured in thefollowing manner.

(1) First one-end-open non-conductive surface 25 a is provided inconductive substrate 10 in parallel to a part of the outer perimeter ofconductive substrate 10, so as to form first linear element portion 30 abetween the part of the outer perimeter and first one-end-opennon-conductive surface 25 a,

(2) second one-end-open non-conductive surface 25 b is provided inconductive substrate 10 in parallel to first one-end-open non-conductivesurface 25 a, so as to form second linear element portion 30 b having alength longer than first linear element portion 30 a between secondone-end-open non-conductive surface 25 b and first one-end-opennon-conductive surface 25 a,

(3) a closed rectangle shaped non-conductive surface is provided inconductive substrate 10 in parallel to second one-end-opennon-conductive surface 25 b, so as to form slot element portion 24,

(4) non-conductive portion 28 is provided in feeding point formingconductive portion 23 formed between second linear element portion 30 band slot element portion 24, so as to use opposing ends ofnon-conductive portion 28 as composite element feeding point 14,

(5) first linear element portion 30 a and feeding point formingconductor portion 23 are connected to each other by first conductorportion 31, and

(6) remaining conductive substrate 10 other than the two linear elementportions, slot element portion 24, and feeding point forming conductiveportion 23 is used as groundplate portion 21.

In FIG. 13, broad-band plate antenna 12, in which one-end-open gapportion 25 or slot element portion 24 is formed by using a conductor forconductive substrate 10 and cutting and removing the conductor, isstructured in the following manner.

(1) First one-end-open gap portion 25 a is provided in conductivesubstrate 10 in parallel to a part of the outer perimeter of conductivesubstrate 10, so as to form first linear element portion 30 a betweenthe part of the outer perimeter and first one-end-open gap portion 25 a,

(2) second one-end-open gap portion 25 b is provided in conductivesubstrate 10 in parallel to first one-end-open gap portion 25 a, so asto form second linear element portion 30 b having a length longer thanfirst linear element portion 30 a between second one-end-open gapportion 25 b and first one-end-open gap portion 25 a,

(3) a slot is provided in conductive substrate 10 in parallel to secondone-end-open gap portion 25 b, so as to form slot element portion 24,

(4) opening portion 28 is provided in feeding point forming conductorportion 23 formed between second linear element portion 30 b and slotelement portion 24, so as to use opposing ends of opening portion 28 ascomposite element feeding point 14,

(5) first linear element portion 30 a and feeding point formingconductor portion 23 are connected to each other by first conductorportion 31, and

(6) remaining conductive substrate 10 other than the two linear elementportions, slot element portion 24, and feeding point forming conductorportion 23 is used as groundplate portion 21.

In FIG. 13, a dimension of broad-band plate antenna 12 is assumed asfollows. Specifically, a: a length in a direction in parallel to thelinear element portion and the slot element portion of conductivesubstrate 10; b: a length in a direction orthogonal to the linearelement portion and the slot element portion of conductive substrate 10;c1: a width of first one-end-open gap portion 25 a; c2: a width ofsecond one-end-open gap portion 25 b; d1: a length of first linearelement portion 30 a; d2: a length of second linear element portion 30b; e1: a width of first linear element portion 30 a; e2: a width ofsecond linear element portion 30 b; f: a width ofeach-element-groundplate commonly short-circuiting conductive portion26; g: a length of slot element portion 24; h: a width of feeding pointforming conductor portion 23; i: a width of slot element portion 24; j:a width of a slot element-groundplate short-circuiting portion 27; andk: a length of opening portion 28. In addition, composite elementfeeding point 14 is formed by feeding point 14 a (hereinafter, referredto as one feeding point 14 a) of feeding point forming conductor portion23 and feeding point 14 b (hereinafter, referred to as the other feedingpoint 14 b) of each-element-groundplate commonly short-circuitingconductive portion 26 or second linear element portion 30 b in proximityof each-element-groundplate commonly short-circuiting conductive portion26.

In broad-band plate antenna 12, length d1 of first linear elementportion 30 a and length d2 of second linear element portion 30 b are oddmultiple of approximately ¼ wavelength of the operation frequency.Length g of slot element portion 24 is integer multiple of approximately½ wavelength of the operation frequency. Different operation frequenciesare selected as the operation frequency for first linear element portion30 a, the operation frequency for second linear element portion 30 b andthe operation frequency for slot element portion 24 respectively, sothat an element-integrated antenna adapted to three operation frequencybands can be obtained. In addition, adjacent operation frequencies areselected as the operation frequency for first linear element portion 30a, the operation frequency for second linear element portion 30 b andthe operation frequency for slot element portion 24 respectively, sothat an element-integrated antenna adapted to continuous and broadoperation frequency bands can be obtained.

In addition, in order to insulate between first conductor portion 31 andsecond linear element portion 30 b, one or both of first conductorportion 31 and second linear element portion 30 b is desirably coveredby an insulator. A wire, a tape-like conductor, a conductor obtained bycovering the former, or a coated cable implements first conductorportion 31. A connection point or a junction of first conductor portion31 connecting first linear element portion 30 a to feeding point formingconductor portion 23 is joined, for example, by soldering. A surface onwhich the feeding point of conductive substrate 10 is joined to afeeding cable, the feeding line, the coaxial cable, or the like may beflush with, or opposed to, a surface on which first conductor portion 31is joined to the feeding point.

Example 5 According to Second Invention

According to Example 5 of the second invention, as shown in FIG. 13,there is provided broad-band plate antenna 12 in which a plurality oflinear element portions and a slot element portion are integrallyformed, wherein

first one-end-open gap portion 25 a is provided in conductive substrate10 in parallel to a part of the outer perimeter of conductive substrate10, so as to form first linear element portion 30 a between the part ofthe outer perimeter and first one-end-open gap portion 25 a,

second one-end-open gap portion 25 b is provided in conductive substrate10 in parallel to first one-end-open gap portion 25 a, so as to formsecond linear element portion 30 b having a length longer than firstlinear element portion 30 a between second one-end-open gap portion 25 band first one-end-open gap portion 25 a,

a slot is provided in conductive substrate 10 in parallel to secondone-end-open gap portion 25 b, so as to form slot element portion 24,

opening portion 28 is provided in feeding point forming conductorportion 23 formed between second linear element portion 30 b and slotelement portion 24, and a conductive portion commonly short-circuitingeach element to groundplate portion 21 is identified aseach-element-groundplate commonly short-circuiting conductive portion26,

one feeding point 14 a connected to opposing ends of opening portion 28is provided in feeding point forming conductor portion 23, and the otherfeeding point 14 b is provided in a protruding portion formed at aconnection portion of each-element-groundplate commonly short-circuitingconductive portion 26 and second linear element portion 30 b (secondconductor portion 32 a protruding from element-groundplateshort-circuiting connection portion),

first linear element portion 30 a and feeding point forming conductorportion 23 are connected to each other by first conductor portion 31,and

remaining conductive substrate 10 other than the plurality of linearelement portions, slot element portion 24, and feeding point formingconductor portion 23 is used as groundplate portion 21.

Example 6 According to Second Invention

According to Example 6 of the second invention, as shown in FIG. 14,there is provided broad-band plate antenna 12 in which a plurality oflinear element portions and a slot element portion are integrallyformed, wherein

first one-end-open gap portion 25 a is provided in conductive substrate10 in parallel to a part of the outer perimeter of conductive substrate10, so as to form first linear element portion 30 a between the part ofthe outer perimeter and first one-end-open gap portion 25 a,

second one-end-open gap portion 25 b is provided in conductive substrate10 in parallel to first one-end-open gap portion 25 a, so as to formsecond linear element portion 30 b having a length longer than firstlinear element portion 30 a between second one-end-open gap portion 25 band first one-end-open gap portion 25 a,

a slot is provided in conductive substrate 10 in parallel to secondone-end-open gap portion 25 b, so as to form slot element portion 24,

opening portion 28 is provided in feeding point forming conductorportion 23 formed between second linear element portion 30 b and slotelement portion 24, and a conductive portion commonly short-circuitingeach element to groundplate portion 21 is identified aseach-element-groundplate commonly short-circuiting conductive portion26,

one feeding point 14 a connected to opposing ends of opening portion 28is provided in feeding point forming conductor portion 23, and the otherfeeding point 14 b is provided in a protruding portion ofeach-element-groundplate commonly short-circuiting conductive portion 26(second conductor portion 32 b protruding from theeach-element-groundplate commonly short-circuiting conductive portion),

first linear element portion 30 a and feeding point forming conductorportion 23 are connected to each other by first conductor portion 31,and

remaining conductive substrate 10 other than the plurality of linearelement portions, slot element portion 24, and feeding point formingconductor portion 23 is used as groundplate portion 21.

Example 7 According to Second Invention

According to Example 7 of the second invention, as shown in FIG. 15,there is provided broad-band plate antenna 12 in which a plurality oflinear element portions and a slot element portion are integrallyformed, wherein

first one-end-open gap portion 25 a is provided in conductive substrate10 in parallel to a part of the outer perimeter of conductive substrate10, so as to form first linear element portion 30 a between the part ofthe outer perimeter and first one-end-open gap portion 25 a,

second one-end-open gap portion 25 b is provided in conductive substrate10 in parallel to first one-end-open gap portion 25 a, so as to formsecond linear element portion 30 b having a length longer than firstlinear element portion 30 a between second one-end-open gap portion 25 band first one-end-open gap portion 25 a,

a slot is provided in conductive substrate 10 in parallel to secondone-end-open gap portion 25 b, so as to form slot element portion 24,

opening portion 28 is provided in feeding point forming conductorportion 23 formed between second linear element portion 30 b and slotelement portion 24, and a conductive portion commonly short-circuitingeach element to groundplate portion 21 is identified aseach-element-groundplate commonly short-circuiting conductive portion26,

one feeding point 14 a connected to opposing ends of opening portion 28is provided in feeding point forming conductor portion 23, and the otherfeeding point 14 b is provided in a protruding portion of second linearelement portion 30 b (second conductor portion 32 c protruding from thesecond element portion),

first linear element portion 30 a and feeding point forming conductorportion 23 are connected to each other by first conductor portion 31,and

remaining conductive substrate 10 other than the plurality of linearelement portions, slot element portion 24, and feeding point formingconductor portion 23 is used as groundplate portion 21.

Example 8 According to Third Invention

According to Example 8 of the third invention, as shown in FIG. 16,there is provided a broad-band plate antenna in which a plurality oflinear element portions are integrally formed according to the thirdinvention, wherein a composite element portion is formed by first linearelement portion 30 a to third linear element portion 30 c, second linearelement portion 30 b has a length longer than first linear elementportion 30 a, third linear element portion 30 c has a length shorterthan second linear element portion 30 b, an area of a non-conductiveportion between second linear element portion 30 b and groundplateportion 21 is made larger, a conductive portion commonlyshort-circuiting each element to groundplate portion 21 is identified aseach-element-groundplate commonly short-circuiting conductive portion26, one feeding point 14 a is provided in second linear element portion30 b, the other feeding point 14 b is provided in third linear elementportion 30 c, and first linear element portion 30 a and third linearelement portion 30 c are connected to each other by first conductorportion 31.

Broad-band plate antenna 20 in which a plurality of linear elementportions are integrally formed shown in FIG. 16 is structured in thefollowing manner.

(1) First one-end-open non-conductive surface 25 a is provided inconductive substrate 10 in parallel to a part of the outer perimeter ofconductive substrate 10, so as to form first linear element portion 30 abetween the part of the outer perimeter and first one-end-opennon-conductive surface 25 a,

(2) second one-end-open non-conductive surface 25 b is provided inconductive substrate 10 in parallel to first one-end-open non-conductivesurface 25 a, so as to form second linear element portion 30 b having alength longer than first linear element portion 30 a between secondone-end-open non-conductive surface 25 b and first one-end-opennon-conductive surface 25 a,

(3) third one-end-open gap portion 25 c is provided in the conductivesubstrate in parallel to second one-end-open non-conductive surface 25b, so as to form third linear element portion 30 c having a lengthshorter than second linear element portion 30 b between thirdone-end-open non-conductive surface 25 c and second one-end-opennon-conductive surface 25 b, an area of second linear element portion 30b and an area of a non-conductive portion between second linear elementportion 30 b and groundplate portion 21 are made larger, and aconductive portion commonly short-circuiting each element to thegroundplate portion is identified as each-element-groundplate commonlyshort-circuiting conductive portion 26,

(4) one feeding point 14 a is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of second linear element portion 30 b,

(5) the other feeding point 14 b is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of third linear element portion 30 c, and

(6) an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of first linear element portion30 a and an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of third linear element portion30 c are connected to each other by first conductor portion 31.

In FIG. 16, broad-band plate antenna 20 in which a plurality of linearelement portions are integrally formed, wherein one-end-open gap portion25 and second linear element portion 30 b are formed by using aconductor for conductive substrate 10 and cutting and removing theconductor, is structured in the following manner.

(1) First one-end-open gap portion 25 a is provided in conductivesubstrate 10 in parallel to a part of the outer perimeter of conductivesubstrate 10, so as to form first linear element portion 30 a betweenthe part of the outer perimeter and first one-end-open gap portion 25 a,

(2) second one-end-open gap portion 25 b is provided in conductivesubstrate 10 in parallel to first one-end-open gap portion 25 a, so asto form second linear element portion 30 b having a length longer thanfirst linear element portion 30 a between second one-end-open gapportion 25 b and first one-end-open gap portion 25 a,

(3) third one-end-open gap portion 25 c is provided in the conductivesubstrate in parallel to second one-end-open gap portion 25 b, so as toform third linear element portion 30 c having a length shorter thansecond linear element portion 30 b between third one-end-open gapportion 25 c and second one-end-open non-conductive surface 25 b, anarea of second linear element portion 30 b and an area of a gap portionbetween second linear element portion 30 b and groundplate portion 21are made larger, and a conductive portion commonly short-circuiting eachelement to the groundplate portion is identified aseach-element-groundplate commonly short-circuiting conductive portion26,

(4) one feeding point 14 a is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of second linear element portion 30 b,

(5) the other feeding point 14 b is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of third linear element portion 30 c, and

(6) an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of first linear element portion30 a and an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of third linear element portion30 c are connected to each other by first conductor portion 31.

Example 9 According to Third Invention)

According to Example 9 of the third invention, as shown in FIG. 1, thereis provided a broad-band plate antenna in which a plurality of linearelement portions are integrally formed according to the third invention,wherein a composite element portion is formed by first linear elementportion 30 a to third linear element portion 30 c, second linear elementportion 30 b has a length longer than first linear element portion 30 aand third linear element portion 30 c, an area of second linear elementportion 30 b is made larger in a direction of first linear elementportion 30 a, third linear element portion 30 c has a length shorterthan second linear element portion 30 d of which area has been madelarger, an area of a non-conductive portion between second linearelement portion 30 b and groundplate portion 21 is made larger, aconductive portion commonly short-circuiting each element to groundplateportion 21 is identified as each-element-groundplate commonlyshort-circuiting conductive portion 26, one feeding point 14 a isprovided in second linear element portion 30 b, the other feeding point14 b is provided in third linear element portion 30 c, and first linearelement portion 30 a and third linear element portion 30 c are connectedto each other by first conductor portion 31.

Broad-band plate antenna 20 in which a plurality of linear elementportions are integrally formed shown in FIG. 1 is structured in thefollowing manner.

(1) First one-end-open non-conductive surface 25 a is provided inconductive substrate 10 in parallel to a part of the outer perimeter ofconductive substrate 10, so as to form first linear element portion 30 abetween the part of the outer perimeter and first one-end-opennon-conductive surface 25 a,

(2) second one-end-open non-conductive surface 25 b is provided inconductive substrate 10 in parallel to first one-end-open non-conductivesurface 25 a, so as to form second linear element portion 30 c having alength longer than first linear element portion 30 a and an area madelarger in a direction of first linear element portion 30 a betweensecond one-end-open non-conductive surface 25 b and first one-end-opennon-conductive surface 25 a,

(3) third one-end-open gap portion 25 c is provided in the conductivesubstrate in parallel to second one-end-open non-conductive surface 25b, so as to form third linear element portion 30 c having a lengthshorter than second linear element portion 30 b between thirdone-end-open gap portion 25 c and second one-end-open non-conductivesurface 25 b, and an area of a non-conductive portion between secondlinear element portion 30 b and groundplate portion 21 is made larger,and

a conductive portion commonly short-circuiting each element togroundplate portion 21 is identified as each-element-groundplatecommonly short-circuiting conductive portion 26,

(4) one feeding point 14 a is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of second linear element portion 30 d,

(5) the other feeding point 14 b is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of third linear element portion 30 c, and

(6) an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of first linear element portion30 a and an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of third linear element portion30 c are connected to each other by first conductor portion 31.

In FIG. 1, broad-band plate antenna 20 in which a plurality oflinear-element portions are integrally formed, wherein one-end-open gapportion 25 and each linear element portion 30 are formed by using aconductor for conductive substrate 10 and cutting and removing theconductor, is structured in the following manner.

(1) First one-end-open gap portion 25 a is provided in conductivesubstrate 10 in parallel to a part of the outer perimeter of conductivesubstrate 10, so as to form first linear element portion 30 a betweenthe part of the outer perimeter and first one-end-open gap portion 25 a,

(2) second one-end-open gap portion 25 b is provided in conductivesubstrate 10 in parallel to first one-end-open gap portion 25 a, so asto form second linear element portion 30 d having a length longer thanfirst linear element portion 30 a and an area made larger in a directionof first linear element portion 30 a between second one-end-open gapportion 25 b and first one-end-open gap portion 25 a,

(3) third one-end-open gap portion 25 c is provided in the conductivesubstrate in parallel to second one-end-open gap portion 25 b, so as toform third linear element portion 30 c having a length shorter thansecond linear element portion 30 b between third one-end-open gapportion 25 c and second one-end-open gap portion 25 b, an area of a gapportion between second linear element portion 30 b and groundplateportion 21 is made larger, and a conductive portion commonlyshort-circuiting each element to groundplate portion 21 is identified aseach-element-groundplate commonly short-circuiting conductive portion26,

(4) one feeding point 14 a is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of second linear element portion 30 d,

(5) the other feeding point 14 b is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of third linear element portion 30 c, and

(6) an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of first linear element portion30 a and an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of third linear element portion30 c are connected to each other by first conductor portion 31.

Example 10 According to Third Invention

According to Example 10 of the third invention, as shown in FIG. 17,there is provided a broad-band plate antenna in which a plurality oflinear element portions are integrally formed according to the thirdinvention, wherein a composite element portion is formed by first linearelement portion 30 a to third linear element portion 30 c, second linearelement portion 30 b has a length longer than first linear elementportion 30 a and third linear element portion 30 c, third linear elementportion 30 c has a length shorter than a second linear element portion30 e of which area has been made larger, an area of a non-conductiveportion between second linear element portion 30 b and groundplateportion 21 is made larger, a conductive portion commonlyshort-circuiting each element to groundplate portion 21 is identified aseach-element-groundplate commonly short-circuiting conductive portion26, one feeding point 14 a is provided in second linear element portion30 b, the other feeding point 14 b is provided in third linear elementportion 30 c, and first linear element portion 30 a and third linearelement portion 30 c are connected to each other by first conductorportion 31.

Broad-band plate antenna 20 in which a plurality of linear elementportions are integrally formed shown in FIG. 17 is structured in thefollowing manner.

(1) First one-end-open non-conductive surface 25 a is provided inconductive substrate 10 in parallel to a part of the outer perimeter ofconductive substrate 10, so as to form first linear element portion 30 abetween the part of the outer perimeter and first one-end-opennon-conductive surface 25 a,

(2) second one-end-open non-conductive surface 25 b is provided inconductive substrate 10 in parallel to first one-end-open non-conductivesurface 25 a, so as to form second linear element portion 30 e having alength longer than first linear element portion 30 a and third linearelement portion 30 c and an area made larger in a direction of firstlinear element portion 30 a and in a direction of third linear elementportion 30 c between second one-end-open non-conductive surface 25 b andfirst one-end-open non-conductive surface 25 a,

(3) third linear element portion 30 c is formed in parallel to secondone-end-open non-conductive surface 25 b, an area of a non-conductiveportion between second linear element portion 30 b and groundplateportion 21 is made larger, and a conductive portion commonlyshort-circuiting each element to groundplate portion 21 is identified aseach-element-groundplate commonly short-circuiting conductive portion26,

(4) one feeding point 14 a is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of second linear element portion 30 e,

(5) the other feeding point 14 b is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of third linear element portion 30 c, and

(6) an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of first linear element portion30 a and an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of third linear element portion30 c are connected to each other by first conductor portion 31.

In FIG. 17, broad-band plate antenna 20 in which a plurality of linearelement portions are integrally formed, wherein one-end-open gap portion25 and each linear element portion 30 are formed by using a conductorfor conductive substrate 10 and cutting and removing the conductor, isstructured in the following manner.

(1) First one-end-open gap portion 25 a is provided in conductivesubstrate 10 in parallel to a part of the outer perimeter of conductivesubstrate 10, so as to form first linear element portion 30 a betweenthe part of the outer perimeter and first one-end-open gap portion 25 a,

(2) second one-end-open gap portion 25 b is provided in conductivesubstrate 10 in parallel to first one-end-open gap portion 25 a, so asto form second linear element portion 30 e having a length longer thanfirst linear element portion 30 a and third linear element portion 30 cand an area made larger in a direction of first linear element portion30 a and in a direction of third linear element portion 30 c betweensecond one-end-open gap portion 25 b and first one-end-open gap portion25 a,

(3) third linear element portion 30 c is formed in parallel to secondone-end-open gap portion 25 b, an area of a gap portion between secondlinear element portion 30 b and groundplate portion 21 is made larger,and a conductive portion commonly short-circuiting each element togroundplate portion 21 is identified as each-element-groundplatecommonly short-circuiting conductive portion 26,

(4) one feeding point 14 a is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of second linear element portion 30 e,

(5) the other feeding point 14 b is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of third linear element portion 30 c, and

(6) an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of first linear element portion30 a and an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of third linear element portion30 c are connected to each other by first conductor portion 31.

Example 11 According to Third Invention

According to Example 11 of the third invention, as shown in FIG. 18,there is provided a broad-band plate antenna in which a plurality oflinear element portions are integrally formed, in the plate antennaincluding conductive substrate 10 forming a composite element portionand groundplate portion 21, wherein

first one-end-open non-conductive surface 25 a is provided in conductivesubstrate 10 in parallel to a part of the outer perimeter of conductivesubstrate 10, so as to form first linear element portion 30 a betweenthe part of the outer perimeter and first one-end-open non-conductivesurface 25 a,

Nth one-end-open non-conductive surface 25 a to Nth one-end-opennon-conductive surface 25 n are provided in conductive substrate 10 inparallel to first one-end-open non-conductive surface 25 a, so as toform second linear element portion 30 b to Nth linear element portion 30n between second one-end-open non-conductive surface 25 b and Nthone-end-open non-conductive surface 25 n, (N−1)th linear element portion30 n-1 second closest to groundplate portion 21 has a length longer than(N−2)th linear element portion 30 n−2 third closest to groundplateportion 21 and Nth linear element portion 30 n closest to groundplateportion 21, an area of (N−1)th linear element portion 30 n−1 is madelarger in a direction of the (N−2)th linear element portion or in adirection of the Nth linear element portion or in the direction of the(N−2)th linear element portion and the direction of the Nth linearelement portion, and an area of a non-conductive portion between (N−1)thlinear element portion 30 n−1 and groundplate portion 21 is made larger,

a conductive portion commonly short-circuiting each element togroundplate portion 21 is identified as each-element-groundplatecommonly short-circuiting conductive portion 26,

one feeding point 14 a is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of (N−1)th linear element portion 30 n−1,

the other feeding point 14 b is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of Nth linear element portion 30 n, and

an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of (N−2)th linear element portion30 n−2 and an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of Nth linear element portion 30n are connected to each other by first conductor portion 31.

Broad-band plate antenna 20 in which a plurality of linear elementportions are integrally formed shown in FIG. 18 is structured in thefollowing manner.

(1) First one-end-open non-conductive surface 25 a is provided inconductive substrate 10 in parallel to a part of the outer perimeter ofconductive substrate 10, so as to form first linear element portion 30 abetween the part of the outer perimeter and first one-end-opennon-conductive surface 25 a,

(2) second one-end-open non-conductive surface 25 b is provided inconductive substrate 10 in parallel to first one-end-open non-conductivesurface 25 a, so as to form second linear element portion 30 b to Nthlinear element portion 30 n between first one-end-open non-conductivesurface 25 a and Nth linear element portion 30 n,

(3) (N−1)th linear element portion 30 n-1 second closest to groundplateportion 21 has a length longer than (N−2)th linear element portion 30n−2 third closest to groundplate portion 21 and Nth linear elementportion 30 n closest to groundplate portion 21, an area of (N−1)thlinear element portion 30 n−1 is made larger (a) in a direction of(N−2)th linear element portion 30 n−2 or (b) in a direction of Nthlinear element portion 30 n or (c) in the direction of (N−2)th linearelement portion 30 n−2 and the direction of Nth linear element portion30 n, an area of a non-conductive portion between (N−1)th linear elementportion 30 n−1 and groundplate portion 21 is made larger, and aconductive portion commonly short-circuiting each element to groundplateportion 21 is identified as each-element-groundplate commonlyshort-circuiting conductive portion 26,

(4) one feeding point 14 a is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of Nth linear element portion 30 n closest to groundplate portion 21,

(5) the other feeding point 14 b is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of (N−1)th linear element portion 30 n-1 second closest to groundplateportion 21, and

(6) an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of (N−2)th linear element portion30 n−2 and an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of Nth linear element portion 30n closest to groundplate portion 21 are connected to each other by firstconductor portion 31.

In FIG. 18, broad-band plate antenna 20 in which a plurality of linearelement portions are integrally formed, wherein one-end-open gap portion25 and each linear element portion 30 are formed by using a conductorfor conductive substrate 10 and cutting and removing the conductor, isstructured in the following manner.

(1) First one-end-open gap portion 25 a is provided in conductivesubstrate 10 in parallel to a part of the outer perimeter of conductivesubstrate 10, so as to form first linear element portion 30 a betweenthe part of the outer perimeter and first one-end-open gap portion 25 a,

(2) second one-end-open gap portion 25 b to Nth one-end-open gap portion25 n are provided in conductive substrate 10 in parallel to firstone-end-open gap portion 25 a, so as to form second linear elementportion 30 b to Nth linear element portion 30 n between secondone-end-open gap portion 25 b and Nth one-end-open gap portion 25 n,

(3) (N−1)th linear element portion 30 n-1 second closest to groundplateportion 21 has a length longer than (N−2)th linear element portion 30n−2 third closest to groundplate portion 21 and Nth linear elementportion 30 n closest to groundplate portion 21, an area of (N−1)thlinear element portion 30 n−1 is made larger (a) in a direction of(N−2)th linear element portion 30 n−2 or (b) in a direction of Nthlinear element portion 30 n or (c) in the direction of (N−2)th linearelement portion 30 n−2 and the direction of Nth linear element portion30 n, an area of a gap portion between (N−1)th linear element portion 30n−1 and groundplate portion 21 is made larger, and a conductive portioncommonly short-circuiting each element to groundplate portion 21 isidentified as each-element-groundplate commonly short-circuitingconductive portion 26,

(3) one feeding point 14 a is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of Nth linear element portion 30 n closest to groundplate portion 21,

(4) the other feeding point 14 b is provided in the vicinity ofeach-element-groundplate commonly short-circuiting conductive portion 26of (N−1)th linear element portion 30 n-1 second closest to groundplateportion 21, and

(5) an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of (N−2)th linear element portion30 n−2 and an area in the vicinity of each-element-groundplate commonlyshort-circuiting conductive portion 26 of Nth linear element portion3 onclosest to groundplate portion 21 are connected to each other by firstconductor portion 31.

[Effect of Third Invention]

An effect of the third invention will be described with reference toFIG. 19. FIG. 19 illustrates a reflection property of the broad-bandplate antenna in which a plurality of linear element portions areintegrally formed according to the third invention shown in FIG. 1, inwhich the abscissa represents an operation frequency [GHz] input/outputto the feeding point of broad-band plate antenna 20 in which a pluralityof linear element portions are integrally formed, while the ordinaterepresents reflection loss (return loss) [dB] specified by a shape of anantenna for each frequency, similarly to FIG. 12 above.

In FIG. 19, a solid line S3 represents a reflection property ofbroad-band plate antenna 20 in which a plurality of linear elementportions are integrally formed according to Example 9 of the thirdinvention shown in FIG. 1. A dashed line S2 represents a reflectionproperty of the broad-band plate antenna in which a plurality of linearelement portions and a slot element portion are integrally formedaccording to Example 4 of the second invention shown in FIG. 13. In thefollowing, description will be given based on comparison of thereflection property of the third invention shown in FIG. 1 with thereflection property of the second invention shown in FIG. 13.

(a) As in FIG. 12 shown above, property S3 a forming reflection propertyS3 is obtained by contribution mainly of second linear element portion22 b of the integral broad-band plate antenna shown in FIG. 16. PropertyS3 bc is the reflection property obtained by contribution mainly offirst linear element portion 22 a and third linear element portion 22 c.

Property S3 bc is brought closer to the operation frequency of firstlinear element portion 22 a and third linear element portion 22, so asto achieve an operation band broader than the total of the individualoperation bands, as in FIG. 12 shown above.

(b) In addition, in FIG. 19, dashed line S2 represents a reflectionproperty of broad-band plate antenna 12 in which a plurality of linearelement portions and a slot element portion are integrally formedaccording to Example 4 of the second invention shown in FIG. 13.

As in FIG. 12 shown above, property S2 a is obtained by contributionmainly of second linear element portion 22 b of antenna 12 shown in FIG.13, while property S2 bc is the reflection property obtained bycontribution mainly of first linear element portion 22 a and slotelement portion 24.

Property S2 bc is brought closer to the operation frequency of firstlinear element portion 22 a and third linear element portion 22 c, so asto achieve an operation band broader than the total of the individualoperation bands, as in FIG. 12 shown above.

(c) The operation band can similarly be broadened also in other Examples6 and 7 and the like according to the second invention shown in FIGS.14, 15 and their modifications.

As described previously, in Examples 4 to 6 shown in FIGS. 13 to 15respectively, the operation band of property S2 a is narrower than thatof property S2 bc in FIG. 19. Consequently, when length y1 of thecomposite element portion shown in FIGS. 13 to 15 to be stored in apersonal computer housing is to be shortened, the operation band ofproperty S2 a is further narrowed and the operation band necessary forthe operation may not be obtained, even if the operation band ofproperty S2 bc is sufficient.

In such a case, in Example 8 according to the third invention shown inFIG. 16, as compared with Examples 4 to 6 according to the secondinvention, an area of a gap between second linear element portion 22 band groundplate portion 21 is made larger, so that the operation band ofproperty S3 bc becomes broader than that of property S2 bc, and lengthy1 of the composite element portion can further be shortened.

The broad-band plate antenna according to the first invention to thethird invention described above can operate as a multiband antennaadapted to three or more different operation frequencies.

INDUSTRIAL APPLICABILITY

As the present invention is practically useful in each embodiment asbelow, its industrial applicability is supported.

The broad-band plate antenna according to the first invention is highlyindustrially applicable, because it is suitable for a portableelectronic apparatus that can be adapted to broad-band and multiband andcan obtain originally-intended directivity of a signal from an antennawithout increase in cost and restriction on a dimension, a shape,design, or the like of the portable electronic apparatus due to ahousing space.

The broad-band plate antenna according to the second invention is highlyindustrially applicable, because it is capable of sufficiently excitingfirst linear element portion 30 a even if first linear element portion30 a is shorter than second linear element portion 30 b so thatinfluence by a housing or the like is not exerted locally on a specificfrequency, in addition to attaining the effect of the first invention.

The broad-band plate antenna in which a plurality of linear elementportions are integrally formed according to the third invention ishighly industrially applicable, because it is capable of achieving abroader operation band of the second linear element portion byincreasing an area of second linear element portion 30 b and an area ofa gap portion between second linear element portion 30 b and groundplateportion 21, in addition to attaining the effect of the first inventionand the second invention.

1. A broad-band plate antenna in which a single linear element portionand a slot element portion are integrally formed; wherein a one-end-opennon-conductive surface is provided in a conductive substrate in parallelto a part of an outer perimeter of the conductive substrate, so as toform a linear element portion between the part of the outer perimeterand the one-end-open non-conductive surface, a closed rectangle shapednon-conductive surface is provided in the conductive substrate inparallel to said one-end-open non-conductive surface, so as to form aslot element portion, a non-conductive portion is provided in a feedingpoint forming conductive portion formed between the one-end-opennon-conductive surface and the slot element portion, so as to useopposing ends of said non-conductive portion as a feeding point, andremaining conductive portion of the conductive substrate other than saidlinear element portion, said slot element portion, and said feedingpoint forming conductive portion is used as a groundplate portion.
 2. Abroad-band plate antenna in which a single linear element portion and aslot element portion are integrally formed; wherein a one-end-open gapportion is provided in a conductive substrate in parallel to a part ofan outer perimeter of the conductive substrate, so as to form a linearelement portion between the part of the outer perimeter and theone-end-open gap portion, a slot is provided in the conductive substratein parallel to said one-end-open gap portion, so as to form a slotelement portion, an opening portion is provided in a feeding pointforming conductor portion formed between the one-end-open gap portionand the slot element portion, so as to use opposing ends of the openingportion as a feeding point, and remaining conductive substrate otherthan said linear element portion, said slot element portion, and saidfeeding point forming conductor portion is used as a groundplateportion.
 3. A broad-band plate antenna in which a plurality of linearelement portions and a slot element portion are integrally formed;wherein a first one-end-open non-conductive surface is provided in aconductive substrate in parallel to a part of an outer perimeter of theconductive substrate, so as to form a first linear element portionbetween the part of the outer perimeter and the first one-end-opennon-conductive surface, a second one-end-open non-conductive surface isprovided in the conductive substrate in parallel to said firstone-end-open non-conductive surface, so as to form a second linearelement portion between said second one-end-open non-conductive surfaceand the first one-end-open non-conductive surface, a closed rectangleshaped non-conductive surface is provided in the conductive substrate inparallel to said second one-end-open non-conductive surface, so as toform a slot element portion, a non-conductive portion is provided in afeeding point forming conductive portion formed between the secondlinear element portion and the slot element portion, so as to useopposing ends of said non-conductive portion as a feeding point, andremaining conductive substrate other than said plurality of linearelement portions, said slot element portion, and said feeding pointforming conductive portion is used as a groundplate portion.
 4. Abroad-band plate antenna in which a plurality of linear element portionsand a slot element portion are integrally formed; wherein a firstone-end-open gap portion is provided in a conductive substrate inparallel to a part of an outer perimeter of the conductive substrate, soas to form a first linear element portion between the part of the outerperimeter and the first one-end-open gap portion, a second one-end-opengap portion is provided in the conductive substrate in parallel to saidfirst one-end-open gap portion, so as to form a second linear elementportion between said second one-end-open gap portion and the firstone-end-open gap portion, a slot is provided in the conductive substratein parallel to said second one-end-open gap portion, so as to form aslot element portion, an opening portion is provided in a feeding pointforming conductor portion formed between the second linear elementportion and the slot element portion, so as to use opposing ends of saidopening portion as a feeding point, and remaining conductive substrateother than said plurality of linear element portions, said slot elementportion, and said feeding point forming conductor portion is used as agroundplate portion.
 5. A broad-band plate antenna in which a pluralityof linear element portions and a slot element portion are integrallyformed; wherein a first one-end-open non-conductive surface is providedin a conductive substrate in parallel to a part of an outer perimeter ofthe conductive substrate, so as to form a first linear element portionbetween the part of the outer perimeter and the first one-end-opennon-conductive surface, a plurality of one-end-open non-conductivesurfaces consisting of a second one-end-open non-conductive surface toan Nth one-end-open non-conductive surface are provided in theconductive substrate in parallel to said first one-end-opennon-conductive surface, so as to form a plurality of linear elementportions consisting of a second linear element portion to an Nth linearelement portion between said one-end-open non-conductive surfaces, aclosed rectangle shaped non-conductive surface is provided in theconductive substrate in parallel to said Nth one-end-open non-conductivesurface, so as to form a slot element portion, a non-conductive portionis provided in a feeding point forming conductive portion formed betweenthe Nth one-end-open non-conductive surface and the slot elementportion, so as to use opposing ends of said non-conductive portion as afeeding point, and remaining conductive substrate other than saidplurality of linear element portions, said slot element portion, andsaid feeding point forming conductive portion is used as a groundplateportion.
 6. A broad-band plate antenna in which a plurality of linearelement portions and a slot element portion are integrally formed;wherein a first one-end-open non-conductive surface is provided in aconductive substrate in parallel to a part of an outer perimeter of theconductive substrate, so as to form a first linear element portion ofwhich length on an outer peripheral side of the conductive substrate isshorter, between the part of the outer perimeter and the firstone-end-open non-conductive surface, a second one-end-opennon-conductive surface is provided in the conductive substrate inparallel to said first one-end-open non-conductive surface, so as toform a second linear element portion having a length longer than thefirst linear element portion between said second one-end-opennon-conductive surface and the first one-end-open non-conductivesurface, a closed rectangle shaped non-conductive surface is provided inthe conductive substrate in parallel to said second one-end-opennon-conductive surface, so as to form a slot element portion, anon-conductive portion is provided in a feeding point forming conductiveportion formed between the second linear element portion and the slotelement portion, so as to use opposing ends of said non-conductiveportion as a feeding point, the first linear element portion and afeeding point forming conductor portion are connected to each other by afirst conductor portion, and remaining conductive substrate other thansaid plurality of linear element portions, said slot element portion,and said feeding point forming conductive portion is used as agroundplate portion.
 7. A broad-band plate antenna in which a pluralityof linear element portions and a slot element portion are integrallyformed; wherein a first one-end-open gap portion is provided in aconductive substrate in parallel to a part of an outer perimeter of theconductive substrate, so as to form a first linear element portionbetween the part of the outer perimeter and the first one-end-open gapportion, a second one-end-open gap portion is provided in the conductivesubstrate in parallel to said first one-end-open gap portion, so as toform a second linear element portion having a length longer than thefirst linear element portion between said second one-end-open gapportion and the first one-end-open gap portion, a slot is provided inthe conductive substrate in parallel to said second one-end-open gapportion, so as to form a slot element portion, an opening portion isprovided in a feeding point forming conductor portion formed between thesecond linear element portion and the slot element portion, so as to useopposing ends of said opening portion as a feeding point, the firstlinear element portion and the feeding point forming conductor portionare connected to each other by a first conductor portion, and remainingconductive substrate other than said plurality of linear elementportions, said slot element portion, and said feeding point formingconductor portion is used as a groundplate portion.
 8. A broad-bandplate antenna in which a plurality of linear element portions and a slotelement portion are integrally formed; wherein a first one-end-opennon-conductive surface is provided in a conductive substrate in parallelto a part of an outer perimeter of the conductive substrate, so as toform a first linear element portion between the part of the outerperimeter and the first one-end-open non-conductive surface, a pluralityof one-end-open non-conductive surfaces consisting of a secondone-end-open non-conductive surface to an Nth one-end-opennon-conductive surface are provided in the conductive substrate inparallel to said first one-end-open non-conductive surface, so as toform a plurality of linear element portions consisting of a secondlinear element portion to an Nth linear element portion, having a lengthlonger than the first linear element portion, between said one-end-opennon-conductive surfaces, a closed rectangle shaped non-conductivesurface is provided in the conductive substrate in parallel to said Nthone-end-open non-conductive surface, so as to form a slot elementportion, a non-conductive portion is provided in a feeding point formingconductive portion formed between the Nth one-end-open non-conductivesurface and the slot element portion, so as to use opposing ends of saidnon-conductive portion as a feeding point, the first linear elementportion and a feeding point forming conductor portion are connected toeach other by a first conductor portion, and remaining conductivesubstrate other than said plurality of linear element portions, saidslot element portion, and said feeding point forming conductive portionis used as a groundplate portion.
 9. A broad-band plate antennaincluding a conductive substrate forming a composite element portion anda groundplate portion; wherein a first one-end-open non-conductivesurface is provided in the conductive substrate in parallel to a part ofan outer perimeter of the conductive substrate, so as to form a firstlinear element portion between the part of the outer perimeter and thefirst one-end-open non-conductive surface, a second one-end-opennon-conductive surface is provided in the conductive substrate inparallel to said first one-end-open non-conductive surface, so as toform a second linear element portion having a length longer than thefirst linear element portion between said second one-end-opennon-conductive surface and the first one-end-open non-conductivesurface, a third one-end-open non-conductive surface is provided in theconductive substrate in parallel to said second one-end-opennon-conductive surface, so as to form a third linear element portionhaving a length shorter than the second linear element portion betweensaid third one-end-open non-conductive surface and the secondone-end-open non-conductive surface, and an area of a non-conductiveportion between the second linear element portion and the groundplateportion is made larger, a conductive portion commonly short-circuitingeach element to the groundplate portion is identified aseach-element-groundplate commonly short-circuiting conductive portion,one feeding point is provided in vicinity of saideach-element-groundplate commonly short-circuiting conductive portion ofthe second linear element portion, the other feeding point is providedin vicinity of said each-element-groundplate commonly short-circuitingconductive portion of the third linear element portion, and the firstlinear element portion and the third linear element portion areconnected to each other by a first conductor portion.
 10. A broad-bandplate antenna including a conductive substrate forming a compositeelement portion and a groundplate portion; wherein a first one-end-opengap portion is provided in the conductive substrate in parallel to apart of an outer perimeter of the conductive substrate, so as to form afirst linear element portion between the part of the outer perimeter andthe first one-end-open gap portion, a second one-end-open gap portion isprovided in the conductive substrate in parallel to said firstone-end-open gap portion, so as to form a second linear element portionhaving a length longer than the first linear element portion betweensaid second one-end-open gap portion and the first one-end-open gapportion, a third one-end-open gap portion is provided in the conductivesubstrate in parallel to said second one-end-open gap portion, so as toform a third linear element portion having a length shorter than thesecond linear element portion between said third one-end-open gapportion and the second one-end-open gap portion, and an area of a gapportion between the second linear element portion and the groundplateportion is made larger, a conductive portion commonly short-circuitingeach element to the groundplate portion is identified aseach-element-groundplate commonly short-circuiting conductive portion,one feeding point is provided in vicinity of saideach-element-groundplate commonly short-circuiting conductive portion ofthe second linear element portion, the other feeding point is providedin vicinity of said each-element-groundplate commonly short-circuitingconductive portion of the third linear element portion, and the firstlinear element portion and the third linear element portion areconnected to each other by a first conductor portion.
 11. A broad-bandplate antenna including a conductive substrate forming a compositeelement portion and a groundplate portion; wherein a first one-end-opennon-conductive surface is provided in the conductive substrate inparallel to a part of an outer perimeter of the conductive substrate, soas to form a first linear element portion between the part of the outerperimeter and the first one-end-open non-conductive surface, a secondone-end-open non-conductive surface is provided in the conductivesubstrate in parallel to said first one-end-open non-conductive surface,so as to form a second linear element portion having a length longerthan the first linear element portion and an area made larger in adirection of the first linear element portion between said secondone-end-open non-conductive surface and the first one-end-opennon-conductive surface, a third one-end-open non-conductive surface isprovided in the conductive substrate in parallel to said secondone-end-open non-conductive surface, so as to form a third linearelement portion having a length shorter than the second linear elementportion between said third one-end-open non-conductive surface and thesecond one-end-open non-conductive surface, and an area of anon-conductive portion between the second linear element portion and thegroundplate portion is made larger, a conductive portion commonlyshort-circuiting each element to the groundplate portion is identifiedas each-element-groundplate commonly short-circuiting conductiveportion, one feeding point is provided in vicinity of saideach-element-groundplate commonly short-circuiting conductive portion ofthe second linear element portion, the other feeding point is providedin vicinity of said each-element-groundplate commonly short-circuitingconductive portion of the third linear element portion, and the firstlinear element portion and the third linear element portion areconnected to each other by a first conductor portion.
 12. A broad-bandplate antenna including a conductive substrate forming a compositeelement portion and a groundplate portion; wherein a first one-end-opengap portion is provided in the conductive substrate in parallel to apart of an outer perimeter of the conductive substrate, so as to form afirst linear element portion between the part of the outer perimeter andthe first one-end-open gap portion, a second one-end-open gap portion isprovided in the conductive substrate in parallel to said firstone-end-open gap portion, so as to form a second linear element portionhaving a length longer than the first linear element portion and an areamade larger in a direction of the first linear element portion betweensaid second one-end-open gap portion and the first one-end-open gapportion, a third one-end-open gap portion is provided in the conductivesubstrate in parallel to said second one-end-open gap portion, so as toform a third linear element portion having a length shorter than thesecond linear element portion between said third one-end-open gapportion and the second one-end-open gap portion, and an area of a gapportion between the second linear element portion and the groundplateportion is made larger, a conductive portion commonly short-circuitingeach element to the groundplate portion is identified aseach-element-groundplate commonly short-circuiting conductive portion,one feeding point is provided in vicinity of saideach-element-groundplate commonly short-circuiting conductive portion ofthe second linear element portion, the other feeding point is providedin vicinity of said each-element-groundplate commonly short-circuitingconductive portion of the third linear element portion, and the firstlinear element portion and the third linear element portion areconnected to each other by a first conductor portion.
 13. A broad-bandplate antenna including a conductive substrate forming a compositeelement portion and a groundplate portion; wherein a first one-end-opennon-conductive surface is provided in the conductive substrate inparallel to a part of an outer perimeter of the conductive substrate, soas to form a first linear element portion between the part of the outerperimeter and the first one-end-open non-conductive surface, a secondone-end-open non-conductive surface is provided in the conductivesubstrate in parallel to said first one-end-open non-conductive surface,so as to form a second linear element portion having a length longerthan the first linear element portion and an area made larger in adirection of the first linear element portion and in a directionopposite to the first linear element portion between said secondone-end-open non-conductive surface and the first one-end-opennon-conductive surface, a third one-end-open non-conductive surface isprovided in the conductive substrate in parallel to said secondone-end-open non-conductive surface, so as to form a third linearelement portion having a length shorter than the second linear elementportion between said third one-end-open non-conductive surface and thesecond one-end-open non-conductive surface, an area of a non-conductiveportion between the second linear element portion and the groundplateportion is made larger, and a conductive portion commonlyshort-circuiting each element to the groundplate portion is identifiedas each-element-groundplate commonly short-circuiting conductiveportion, one feeding point is provided in vicinity of saideach-element-groundplate commonly short-circuiting conductive portion ofthe second linear element portion, the other feeding point is providedin vicinity of said each-element-groundplate commonly short-circuitingconductive portion of the third linear element portion, and the firstlinear element portion and the third linear element portion areconnected to each other by a first conductor portion.
 14. A broad-bandplate antenna including a conductive substrate forming a compositeelement portion and a groundplate portion; wherein a first one-end-opengap portion is provided in the conductive substrate in parallel to apart of an outer perimeter of the conductive substrate, so as to form afirst linear element portion between the part of the outer perimeter andthe first one-end-open gap portion, a second one-end-open gap portion isprovided in the conductive substrate in parallel to said firstone-end-open gap portion, so as to form a second linear element portionhaving a length longer than the first linear element portion and an areamade larger in a direction of the first linear element portion and in adirection opposite to the first linear element portion between saidsecond one-end-open gap portion and the first one-end-open gap portion,a third one-end-open gap portion is provided in the conductive substratein parallel to said second one-end-open non-conductive surface, so as toform a third linear element portion having a length shorter than thesecond linear element portion between said third one-end-open gapportion and the second one-end-open gap portion, and an area of a gapportion between the second linear element portion and the groundplateportion is made larger, a conductive portion commonly short-circuitingeach element to the groundplate portion is identified aseach-element-groundplate commonly short-circuiting conductive portion,one feeding point is provided in vicinity of saideach-element-groundplate commonly short-circuiting conductive portion ofthe second linear element portion, the other feeding point is providedin vicinity of said each-element-groundplate commonly short-circuitingconductive portion of the third linear element portion, and the firstlinear element portion and the third linear element portion areconnected to each other by a first conductor portion.
 15. A broad-bandplate antenna including a conductive substrate forming a compositeelement portion and a groundplate portion; wherein a first one-end-opennon-conductive surface is provided in the conductive substrate inparallel to a part of an outer perimeter of the conductive substrate, soas to form a first linear element portion between the part of the outerperimeter and the first one-end-open non-conductive surface, a secondone-end-open non-conductive surface to an Nth one-end-opennon-conductive surface are provided in the conductive substrate inparallel to said first one-end-open non-conductive surface, so as toform a second linear element portion to an Nth linear element portionbetween said second one-end-open non-conductive surface and the Nthone-end-open non-conductive surface, an (N−1)th linear element portionsecond closest to the groundplate portion has a length longer than an(N−2)th linear element portion third closest to the groundplate portionand an Nth linear element portion closest to the groundplate portion, anarea of the (N−1)th linear element portion is made larger in a directionof the (N−2)th linear element portion or in a direction of the Nthlinear element portion or in the direction of the (N−2)th linear elementportion and the direction of the Nth linear element portion, and an areaof a non-conductive portion between the (N−1)th linear element portionand the groundplate portion is made larger, a conductive portioncommonly short-circuiting each element to the groundplate portion isidentified as each-element-groundplate commonly short-circuitingconductive portion, one feeding point is provided in vicinity of saideach-element-groundplate commonly short-circuiting conductive portion ofthe (N−1)th linear element portion, the other feeding point is providedin vicinity of said each-element-groundplate commonly short-circuitingconductive portion of the Nth linear element portion, and an area invicinity of said each-element-groundplate commonly short-circuitingconductive portion of the (N−2)th linear element portion and an area invicinity of said each-element-groundplate commonly short-circuitingconductive portion of the Nth linear element portion are connected toeach other by a first conductor portion.
 16. A broad-band plate antennaincluding a conductive substrate forming a composite element portion anda groundplate portion; wherein a first one-end-open gap portion isprovided in the conductive substrate in parallel to a part of an outerperimeter of the conductive substrate, so as to form a first linearelement portion between the part of the outer perimeter and the firstone-end-open gap portion, a second one-end-open gap portion to an Nthone-end-open gap portion are provided in the conductive substrate inparallel to said first one-end-open gap portion, so as to form a secondlinear element portion to an Nth linear element portion between saidsecond one-end-open gap portion and the Nth one-end-open gap portion, an(N−1)th linear element portion second closest to the groundplate portionhas a length longer than an (N−2)th linear element portion third closestto the groundplate portion and an Nth linear element portion closest tothe groundplate portion, an area of the (N−1)th linear element portionis made larger in a direction of the (N−2)th linear element portion orin a direction of the Nth linear element portion or in the direction ofthe (N−2)th linear element portion and the direction of the Nth linearelement portion, and an area of a gap portion between the (N−1)th linearelement portion and the groundplate portion is made larger, a conductiveportion commonly short-circuiting each element to the groundplateportion is identified as each-element-groundplate commonlyshort-circuiting conductive portion, one feeding point is provided invicinity of said each-element-groundplate commonly short-circuitingconductive portion of the (N−1)th linear element portion, the otherfeeding point is provided in vicinity of said each-element-groundplatecommonly short-circuiting conductive portion of the Nth linear elementportion, and an area in vicinity of said each-element-groundplatecommonly short-circuiting conductive portion of the (N−2)th linearelement portion and an area in vicinity of said each-element-groundplatecommonly short-circuiting conductive portion of the Nth linear elementportion are connected to each other by a first conductor portion. 17-19.(canceled)